Women with polycystic ovary syndrome (PCO) display disordered patterns of LH pulsatility and may have an impairment of opioidergic regulation of GnRH-LH. In order to ascertain if these patterns reflect an inherent hypothalamic abnormality or a functional state consequent to the acyclicity of sex steroids, LH pulsatility and gonadotrophin responses to naloxone were examined in six PCO women before and after treatment with incremental daily doses of a progestogen, medroxyprogesterone acetate (MPA), for 10 days to determine (i) if progestogen treatment would alter the LH pulse pattern to resemble that of the luteal phase; and (ii) if the conversion to a luteal phase LH pulse pattern by MPA would involve the induction of opioidergic regulation. LH pulsatility and FSH levels were determined by blood sampling at 10 min intervals for 8 h before and after MPA treatment during a saline infusion on the control day and during a naloxone infusion (1.6 mg/h) on the following day. Basal levels of oestradiol, oestrone, androstenedione, testosterone, and dehydroepiandrosterone-sulphate were measured before and after MPA. All six PCO women responded to MPA administration with a significant reduction in LH pulse frequency (P less than 0.005), an increase in LH pulse amplitude (P less than 0.0025), and an increase in LH pulse duration (P less than 0.025), without changes in mean LH, mean FSH, androgen, or oestrogen levels. Thus, a luteal phase LH pulse pattern was induced by MPA. Naloxone reversed the MPA-induced changes in LH pulsatility, indicating that these responses involved the induction of central opioidergic activity.(ABSTRACT TRUNCATED AT 250 WORDS)

OBJECTIVE

To investigate whether body composition, functional status and serum hormone levels are associated with quality of life in healthy postmenopausal women.

METHODS

A cross-sectional study among 402 women aged 56-73 years, 8-30 years postmenopausal. Quality of life (QoL) was assessed using the questionnaire on life satisfaction (QLS), with two modules directed at general factors (QLS-general) and health factors (QLS-health). Muscle strength was measured using dynamometry. Functional ability was estimated by physical performance (PPS), physical activity during the preceding year, and impairment in activities of daily living (ADL). Bone mineral density, lean mass and fat mass were assessed by dual-energy X-ray absorptiometry. Fasting levels of serum oestradiol, oestrone, and sex hormone-binding globulin (SHBG), testosterone, cortisol, androstenedione, DHEA and DHEAS, insulin-like growth factor (IGF-1), its binding proteins (IGFBP-1 and -3) and insulin, were determined.

RESULTS

Both QLS modules did not decrease with age. The major positive predictor of QLS-general module was the presence of a partner. Higher physical performance and higher educational level of participants' partners were significantly related to higher QLS-general, while smoking and presence of co-morbidities were significantly associated with a lower QLS-general. The determinants studied were mostly related to the QLS-health module, the major negative predictor of QLS-health being the presence of co-morbidities, followed by physical activity, physical performance and grip strength. Higher educational level of participants was related with higher QLS-health module, while higher BMI, fat mass and presence of disability were associated with significantly lower QLS-health. No consistent relation was found between serum levels of hormones measured and both QLS modules.

CONCLUSIONS

The most important and specific determinant for psychological well-being was having a partner. Physical and psychological well-being are further strongly associated in this population of healthy postmenopausal women below 75 years of age, while increasing fat mass was related to decreased well-being. Our results suggest that in elderly and late postmenopausal women hormonal factors do not predict quality of life.

An enzyme that conjugates the 16alpha-hydroxyl group of oestriol with glucuronic acid was found in the cytosol fraction of human liver. The enzymic activity could not be sedimented when the cytosol fraction was centrifuged at 158000g(av.) for 120min. The oestriol 16alpha-glucuronyltransferase was purified 100-fold by 0-30% saturation of the cytosol fraction with ammonium sulphate followed by filtration of the precipitate through Sephadex G-200. The activity was eluted at the void volume. The product of the reaction, oestriol 16alpha-monoglucuronide, was identified by paper chromatography and by crystallization of radioactive product to constant specific radioactivity. The optimum temperature was 37 degrees C, and the activation energy was calculated to be 11.1kcal/mol. The apparent Michaelis-Menten constants for oestriol and UDP-glucuronic acid were 13.3 and 100mum respectively. Cu(2+), Zn(2+) and Hg(2+) inhibited, whereas Mg(2+), Mn(2+) and Fe(2+) stimulated the enzyme. Substrate-specificity studies indicated that the amount of oestradiol-17beta, oestradiol-17alpha and oestrone conjugated was not more than about 5% of that found for oestriol. Oestriol 16alpha-monoglucuronide, a product of the reaction, did not inhibit the 16alpha-oestriol glucuronyltransferase; in contrast, UDP, another product of the reaction, inhibited the enzyme competitively with respect to UDP-glucuronic acid as the substrate, and non-competitively with respect to oestriol as the substrate. ATP and UDP-N-acetylglucosamine did not affect the oestriol 16alpha-glucuronyltransferase. 17-Epioestriol acted as a competitive inhibitor and 16-epioestriol as a non-competitive inhibitor of the glucuronidation of oestriol. 5alpha-Pregnane-3alpha,20alpha-diol also inhibited the enzyme non-competitively. It is most likely that the oestriol 16alpha-glucuronyltransferase described here is bound to the membranes of the endoplasmic reticulum.

Aminoglutethimide is an aromatase inhibitor that is successfully used for endocrine treatment of advanced breast cancer. This drug also stimulates the activity of hepatic mixed-function oxidases, increasing the metabolism of several drugs, including warfarin, digitoxin, antipyrine and theophylline. It also increases the plasma clearance rate of oestrone sulphate. As this oestrogen may be an important substrate for tumour cells, stimulation of oestrone sulphate metabolism may be a component of the mechanism of action of aminoglutethimide.

In a prospective study we have measured serum levels of sex hormone-binding globulin (SHBG), androgens, oestrogens and gonadotropins in 20 male IDDM patients with the aim of evaluating the effect of improved glycaemic control on these levels and to compare the IDDM patients with an age- and weight-matched healthy non-diabetic control group. The patients were chosen from the male IDDM patients attending the outpatient clinic at the Department of Endocrinology, Odense University Hospital. Glycaemic control was optimized by a trained diabetologist according to the patients' measurements of home blood glucose concentrations and reported hypoglycaemic episodes during a three month period. Prior to regulation the patients, compared to healthy control subjects, had significantly higher serum levels of oestrone (0.29 +/- 0.02 vs 0.16 +/- 0.01 nmol/l (Mean +/- SEM), p < 0.01), 17 beta-oestradiol (0.12 +/- 0.01 vs 0.08 +/- 0.01 nmol/l, p < 0.01), dihydrotestosterone (4.20 +/- 0.18 vs 1.66 +/- 0.09 nmol/l, p < 0.01), total testosterone (20.7 +/- 0.9 vs 17.8 +/- 1.1 nmol/l, p < 0.05) and SHBG (42.3 +/- 2.9 vs 15.5 +/- 3.5 nmol/l, p < 0.05), while the calculated free-testosterone was lower (0.34 +/- 0.02 vs 0.40 +/- 0.02 nmol/l, p = 0.068). After regulation, the patients obtained significantly lower levels of glycosylated haemoglobin (10.4 +/- 0.3 vs 8.9 +/- 0.2%, p < 0.005) and serum fructosamine (1.50 +/- 0.05 vs 1.34 +/- 0.04 nmol/l, p < 0.005) on a higher 24 hour insulin dose (52.7 +/- 4.4 vs 59.2 +/- 4.6 IU/24 h, p < 0.005). Levels of free-testosterone (0.41 +/- 0.04 nmol/l), oestrone (0.33 +/- 0.03 nmol/l), oestradiol (0.14 +/- 0.01 nmol/l), delta 4-androstenedione (4.44 +/- 0.43 vs 3.85 +/- 0.42 nmol/l), and prolactin (249 +/- 24 vs 200 +/- 19 mIU/l) increased compared to values obtained before regulation (all p < 0.05). We conclude that SHBG, testosterone, dihydrotestosterone and oestrogen levels are increased in male IDDM patients. High SHBG levels tend to keep the free fractions of sex hormones within normal limits. During improvement of glycaemic control with insulin, levels of free-testosterone and its bioprecursors and metabolites rise. This may partly be due to the increased daily insulin dose and/or to the improvement in glycaemic control itself.

Saliva steroid levels reflect the unbound unconjugated (free, biologically active) plasma hormone levels. Saliva oestriol (E3), oestradiol (E2), oestrone (E1) and progesterone levels were estimated by radioimmunoassay in saliva samples obtained twice a week from 18 weeks gestation until 38 days before delivery and then daily until the spontaneous onset of labour at term from 20 normal pregnant women. The overall percentage increases in the median concentrations of E3, E2, E1 and progesterone were 718, 370, 80 and 214%, respectively, in the last 20 weeks and 149, 82, 24 and 41%, respectively, in the last 6 weeks of pregnancy. The median E3:progesterone ratio rose slowly from 0.65 at 20 weeks before delivery to 1.0 at 5 weeks before delivery and then rapidly to 1.65 one day before the spontaneous onset of labour. There was an increase in the E3:progesterone ratio from less than 1 to greater than 1 before labour in every subject.

The effects of liver transplantation on the pituitary-gonadal axis and sex-hormone metabolism were evaluated by studying hormonal status (androgens, oestrogens, and gonadotropins) and sex-hormone-binding globulin levels in men with advanced liver disease of both alcoholic and viral origins. Comparison of the results prior to and 6 months after liver transplantation showed that successful liver transplantation in men induced significant differences in sex-hormone levels and in pituitary-gonadal function in both alcoholic and post-hepatitis patients. Plasma testosterone and dihydrotestosterone levels increased, oestrogen (oestrone and oestradiol) and androstenedione levels fell while gonadotropin (FSH and LH) levels increased. There was also a fall in plasma prolactin levels. Sex-hormone binding globulin plasma levels were elevated prior to transplantation and decreased thereafter. These data show that male patients with advanced liver disease have biological hypogonadism and feminization, irrespective of the aetiology, and that these abnormalities rapidly improve after successful liver transplantation. Therefore in men with advanced liver disease the biochemical signs of sex hormone disturbance are reversible and may be largely related to the liver disease.

The levels of pregnenolone, dehydroepiandrosterone (DHA), androstenedione, testosterone, dihydrotestosterone (DHT), oestrone, oestradiol, cortisol and luteinizing hormone (LH) were measured in the peripheral plasma of a group of young, apparently healthy males before and after masturbation. The same steroids were also determined in a control study, in which the psychological antipation of masturbation was encouraged, but the physical act was not carried out. The plasma levels of all steroids were significantly increased after masturbation, whereas steroid levels remained unchanged in the control study. The most marked changes after masturbation were observed in pregnenolone and DHA levels. No alterations were observed in the plasma levels of LH. Both before and after masturbation plasma levels of testosterone were significantly correlated to those of DHT and oestradiol, but not to those of the other steroids studied. On the other hand, cortisol levels were significantly correlated to those of pregnenolone, DHA, androstenedione and oestrone. In the same subjects, the levels of pregnenolone, DHA, androstenedione, testosterone and DHT, androstenedione and oestrone. In the same subjects, the levels of pregnenolone, DHA, androstenedione, testosterone and DHT in seminal plasma were also estimated; they were all significantly correlated to the levels of the corresponding steroid in the systemic blood withdrawn both before and after masturbation. As a practical consequence, the results indicate that whenever both blood and semen are analysed, blood sampling must precede semen collection.

While intrasexual competition for mates is generally considered to be an androgen-dependent characteristic of reproductively active males, in the Wilson's phalarope (Phalaropus tricolor) it is the female that acquires the brighter nuptial plumage and aggressively competes for access to the less aggressive males. Despite this pronounced sex-role reversal, circulating sex steroid hormones of breeding phalaropes are similar to those of avian species displaying traditional male-female reproductive roles. To investigate whether these behavioural and morphological steroid-dependent differences may be due to differences in target organ metabolism of circulating androgen, [3H]androstenedione in the presence of an NADPH-generating system was incubated with homogenates of brain, pituitary and skin of male and female Wilson's phalaropes collected from a naturally breeding population. Oestrone, 5 alpha-androstanedione and 5 beta-androstanedione were measured as endpoints of aromatization, 5 alpha-reduction and 5 beta-reduction respectively. Aromatase activity in the anterior hypothalamus/preoptic area (AHPOA) and posterior hypothalamus was greater in breeding males with high circulating concentrations of testosterone than in females, and activity in the AHPOA was greater in breeding than in non-breeding males (with low circulating testosterone). Aromatase levels did not differ in septum, archistriatum, hyperstriatum or pituitary. 5 alpha- and 5 beta-reductase were detected in all neuroendocrine tissues sampled and although there were no significant male-female differences, 5 alpha-reductase was greater in the AHPOA of breeding than of nonbreeding males.(ABSTRACT TRUNCATED AT 250 WORDS)

The ABCG2 transporter breast cancer resistance protein (BCRP) has been identified in several physiological sites. It has been suggested to play an important role in disposition of many drugs and environmental toxins. We investigated the effects of several antipsychotic drugs, including risperidone, 9-hydroxy-risperidone (paliperidone), olanzapine, quetiapine, clozapine, haloperidol and chlorpromazine, and a positive control inhibitor Ko143 on functions of BCRP in MCF7 and BCRP over-expressing MCF7/MX100 cell lines using a BCRP prototypical substrate mitoxantrone. Our findings indicated that the tested antipsychotics rank order of potency of inhibition of BCRP according to concentrations required to reach 50% of maximum inhibition (IC(50)) was as follows: Ko143 (0.07 microM)>> risperidone (38.1 microM)>> clozapine (42.0 microM)>> paliperidone (51 microM)>> chlorpromazine (52.2 microM)>> quetiapine (66.1 microM)>> olanzapine = haloperidol (>100.0 microM). We further tested the effects of various concentrations of risperidone on the BCRP-mediated transport of oestrone-3-sulfate in a colon carcinoma cell line, Caco-2, a widely used model to study drug absorption. Our findings show that risperidone at concentrations ranging from 1 to 100 microM significantly inhibited intracellular accumulation of oestrone-3-sulfate in Caco-2 cell monolayers. The present results suggest that a potential source of pharmacokinetic interactions exists between BCRP substrates and several antipsychotics.

1. To assess the possible involvement of ligandin and aminoazo-dye-binding protein A in intracellular transport it is necessary to know how their ligands, most of which are molecules with hydrophobic moieties, interact with cellular membranes. To obtain such information we have examined the interactions of 2-acetylaminofluorene, 4-dimethylaminoazobenzene, oestrone and testosterone with aqueous dispersions of egg phosphatidylcholine and egg phosphatidylcholine/cholesterol (1:1, molar ratio) by equilibrium dialysis and spectrophotometry. 2. At 25 degrees C and pH7.4, the partition coefficients for binding to phosphatidylcholine [expressed as (mol of ligand bound/mol of phosphatidylcholine)/unbound ligand concentration] were: for 2-acetylaminofluorene, 5.0x10(3) litre.mol(-1); for 4-dimethylaminoazobenzene, 2.1x10(4) litre.mol(-1); for oestrone, 3.1x10(3) litre.mol(-1); and for testosterone, 4.2x10(2) litre.mol(-1). In the ranges studied these values were independent of concentration. The results for the two steroids confirm those of Heap, Symons & Watkins [(1970) Biochim. Biophys. Acta218, 482-495]. 3. The introduction of cholesterol into the lipid bilayers caused large decreases in the partition coefficients of oestrone and testosterone, but had relatively little effect on the binding of 2-acetylaminofluorene and 4-dimethylaminoazobenzene. 4. By assuming that the interactions with egg phosphatidylcholine bilayers resemble those with the phospholipid components of mammalian intracellular membranes the phosphatidylcholine partition coefficients, together with data for binding to the intracellular proteins ligandin and aminoazo-dye-binding protein A, enable the subcellular distributions of the four compounds to be estimated. For the rat hepatocyte up to 98, 99, 89 and 58% of the total 2-acetylaminofluorene, 4-dimethylaminoazobenzene, oestrone and testosterone respectively may be membrane-bound.

60 premenopausal women were assessed before and after hysterectomy for menorrhagia or fibroids or both. Their mood, sexual functioning, and plasma oestrogens and gonadotrophins were regularly assessed for a period of up to 3 years. Patients were randomly assigned to receive either oestrone sulphate or placebo tablets during the trial. No evidence was found that this group of patients showed depression or sexual difficulties related to the hysterectomy. In comparison with their baseline gynaecological condition, they showed improved mood and vigour and unimpaired sexual activity.

Many tumours in endocrine-sensitive tissues, such as the breast and endometrium, are hormone-dependent and the hydrolysis of oestrone sulphate (EIS) to oestrone by oestrone sulphatase (EI-STS) is a major source of oestrogen in such tumours. Oestrone-3-O-sulphamate (EMATE) has been shown to be a potent EI-STS inhibitor in vitro, and in this study its ability to inhibit enzyme activity in vivo was examined. EMATE was initially administered to female rats for 7 days, after which liver EI-STS activity was measured. As EMATE also inhibits a related sulphatase in vitro, dehydroepiandrosterone sulphatase (DHA-STS), its effect on the activity of this enzyme in vivo was also investigated. DHA-STS has a pivotal role in regulating the synthesis of another steroid with potent oestrogenic properties, androstenediol. Administration of EMATE almost completely inhibited liver EI-STS (99%) and DHA-STS (99%) activities and was active when given by the oral or subcutaneous routes. After a single dose of EMATE or following the cessation of multiple doses for 10 days, liver EI-STS activity remained inhibited (>> 95%) for up to 7 and 10 days, respectively. Other compounds, such as 4-hydroxytamoxifen and the "pure" antioestrogen ICI 182,780, which are reported to inhibit EI-STS activity in vitro, did not inhibit activity in vivo. In a preliminary study, EMATE, when injected over a 12-day period, effectively reduced the growth of EIS-stimulated nitrosomethyl-urea-induced mammary tumours in ovariectomised rats and inhibited tumour sulphatase activity in treated animals.

An investigation was made of the serum steroid levels found in intact and endocrine ablated nude mice of both sexes and in their intact homozygous littermates. The results showed that nude mice have a normal steroidogenesis, but with decreased levels of circulating steroids compared to those of the littermates. The efficacy of the endocrine ablations was confirmed by the reduction in serum oestrone following oophorectomy, and by the reduction in serum testosterone and progesterone following orchiectomy. The normal steroidogenesis in nude mice, and the similarities between mouse and man with regard to changes in serum steroids following oophorectomy and orchiectomy, support the usefulness of human tumor xenograft models for the study of hormone-tumor interactions.

The uptake of 125-iodide by transplanted hormone-responsive (HR) or hormone-independent (HI) mammary tumors, normal mammary tissue and skeletal muscle was compared in GR mice. The uptake of 125-iodide by HR mammary tumors in mice treated with progesterone and oestrone (P+O) was about 20 times greater than the uptake of 125-iodide by HI mammary tumors in mice not treated with P+O. This difference in uptake of 125-iodide by HR and HI mammary tumors could not be attributed to the difference in the hormonal status of the mice since uptake of 125-iodide was also low in HI tumors in mice receiving P+O treatment. The uptake of 125-iodide by HR mammary tumors was greatly reduced by the simultaneous injection of either an excess of non-radioactive iodide or of perchlorate. Uptake of 125-iodide by normal mammary tissue and skeletal muscle was similar was similar in all groups of tumor bearing mice, and was not influenced by the presence of an excess of non-radioactive iodide or of perchlorate. The possible clinical significance of these findings is discussed.

Synthesis of oestrone from androstenedione within tumours, by the aromatase enzyme complex, is an important source of oestrogen that is available to support the growth of hormone-dependent breast tumours. In view of the central role that the aromatase enzyme has in oestrogen synthesis there has been considerable interest in understanding its regulation and developing inhibitors to block its action. In the present study we have derived fibroblasts from breast tumours (TFs), tissue proximal to tumours (PFs) and reduction mammoplasty tissue (RMFs) and used them to investigate the regulation of aromatase activity by PGE(2), IL-6 plus its soluble receptor (SR) or TNFalpha. In addition we have examined the ability of 2-methoxyoestrone sulphamate (2-MeOEMATE), a compound which alters microtubule stability, to block the stimulation of aromatase activity by these factors. Basal aromatase activity in PFs was significantly higher (p<0.001) than in TFs or RMFs. The combination of IL-6 plus SR or TNFalpha produced the greatest stimulation of aromatase activity in TFs (up to 61-fold) while having a much lower stimulatory effects on aromatase activity in PFs (up to 60% increase) or RMFs (up to 192% increase). 2-MeOEMATE reduced basal aromatase activity in TFs by 87% and completely abrogated the ability of PGE(2), IL-6 plus SR or TNFalpha to stimulate aromatase activity in these fibroblasts. Results from these studies indicate that while PFs have the highest level of non-stimulated aromatase activity, aromatase activity in TFs shows the greatest response to cytokines. These findings suggest that intrinsic difference may exist for the different types of fibroblasts in the way in which they respond to regulatory factors. The ability of 2-MeOEMATE to block cytokine stimulated aromatase activity suggests that, in addition to its other anti-cancer properties, this compound may also act to inhibit cytokine-stimulated aromatase activity in breast tumours.

This study was carried out to determine the effect of sex and oral administration of oleoyl-oestrone on body weight of 12-week-old female and male Zucker obese (fa/fa) rats initially weighing 350-380 g and 405-420 g, respectively. The rats were maintained in standard conditions and given a daily oral gavage of 0.2 ml oleoyl-oestrone dissolved in sunflower oil at a dose of 10 micromol/kg/day for 10 days, and their body weight and food intake was monitored. They were then killed, and their carcass composition (water, lipid, protein and total energy), liver lipids and glycogen and plasma chemistry, insulin, free and total oestrone were measured. Oral administration of oleoyl-oestrone via gavage resulted in significant losses of fat, energy and-ultimately-weight. Treatment with oleoyl-oestrone decreased food intake; the energy expenditure was kept close to that of controls at the expense of internal fat stores. Nevertheless, body protein and plasma metabolite homeostasis were preserved. The slimming effects were more marked in males than in females. Treatment increased circulating acyl-oestrone and reduced to normal levels the high insulin observed in controls. Treatment of genetically obese rats with a daily oral gavage of oleoyl-oestrone resulted in the loss of fat reserves with little modification of other metabolic parameters, except for lower plasma glucose and insulin levels. The results suggest that oleoyl-oestrone, in addition to its slimming effects may be effective as an antidiabetic agent in type 2 diabetes.

BACKGROUND

The expression of the oestrogen receptor (ER) is one of the more important clinical parameters of breast cancer. However, the relationship between the ER and its ligand, oestradiol, and the enzymes that synthesise it are not well understood. The expression of mRNA transcripts of members of the oestradiol metabolic and signalling pathways including the ER was studied in detail.

METHODS

mRNA transcripts for aromatase (CYP19), 17-beta-hydroxysteroid dehydrogenase I, 17-beta-hydroxysteroid dehydrogenase II, ERalpha, ERbeta, steroid sulfatase (STS), oestradiol sulfotransferase (EST), cyclin D1 (CYCLD1) and ERBB2 were fluorometrically quantified by competitive RT-PCR using an internal standard in 155 breast carcinomas. In addition, the transcripts of CYP19 were analysed for alternative splicing/usage of exon 1 and an alternative poly A tail.

RESULTS

A great variability of expression was observed, ranging from 0 to 2376 amol/mg RNA. The highest levels were observed for STS and EST, and the lowest levels (close to zero) were observed for the 17-beta-hydroxysteroid dehydrogenase isoenzymes. The levels of mRNA expression were analysed with respect to clinical and histopathological parameters as well as for disease-free survival. High correlation of the mRNA expression of STS, EST and 17-beta-hydroxysteroid dehydrogenase in the tumours suggested a common regulation, possibly by their common metabolite (oestradiol). Hierarchical clustering analysis in the 155 patients resulted in two main clusters, representing the ERalpha-negative and ERalpha-positive breast cancer cases. The mRNA expression of the oestradiol metabolising enzymes did not follow the expression of the ERalpha in all cases, leading to the formation of several subclasses of tumours. Patients with no expression of CYP19 and patients with high levels of expression of STS had significantly shorter disease-free survival time (P>> 0.0005 and P < 0.03, respectively). Expression of ERbeta mRNA was a better prognostic factor than that of ERalpha in this material.

CONCLUSIONS

Our results indicate the importance of CYP19 and the enzymes regulating the oestrone sulfate metabolism as factors of disease-free survival in breast cancer, in addition to the well-known factors ER and ERBB2.

The hypoestrogenic state induced by gonadotrophin-releasing hormone agonist (GnRHa) has been shown to be effective in the treatment of oestrogen-dependent disorders but to induce bone loss. Adding back low doses of oestrogen in GnRHa therapy has been proposed to prevent bone loss. The purpose of this study is to assess the efficacy of add-back therapy with different natural oestrogens such as oestrone (OE(1)), oestradiol (OE(2)) and oestriol (OE(3)). Three-month-old female rats (250 g) were subcutaneously administered microcapsules of leuprorelin acetate in doses of 1 mg/kg of body weight every 4 weeks. GnRHa therapy lasted 16 weeks, and pellets of OE(1), OE(2) or OE(3) (0.5 mg/pellet, 60 day release), as an add-back agent, were implanted at 8 weeks of treatment. At the end of treatment, GnRHa alone decreased bone mineral density of the femur and lumbar vertebrae, and increased serum levels of bone metabolic markers such as alkaline phosphatase and osteocalcin levels. As for cancellous bone histomorphometry, GnRHa decreased bone volume while it increased osteoid volume, osteoid surface, eroded surface, mineral apposition rate and bone formation rate. All the oestrogens tested prevented these changes caused by GnRHa therapy. GnRHa induced a significant increase in body weight and a marked reduction in uterine weight, which was not observed in OE(1) or OE(2) add-back group. Body weight and uterine weight of the OE(3) add-back group were the same as those of the GnRHa group. These findings indicate that GnRHa induces high turnover bone loss which can be prevented by concomitant administration of natural oestrogens such as OE(1), OE(2) and OE(3) to the same extent. In addition, OE(3) is unique in that it is much less effective than OE(1) and OE(2) in blocking body weight gain and in promoting growth of uterine tissues. Because of its tissue-selective actions, OE(3) could be considered as one of the most appropriate oestrogens used for GnRHa add-back therapy.

Almost a third of the life of a woman is now postmenopausal, and during this period over 80% of endometrial carcinomas develop. This is by far the most common gynaecological malignancy in the industrialised world and, probably, the less completely understood with regard to its pathogenesis after the menopause. For while it is generally thought that these neoplasms are non-oestrogen-induced, we are, at the same time, informed that oestrogenic stimulation is continuous during menopause through increases to oestrone formation in the adipose tissue from androgens of adrenal and ovarian origin. Furthermore, the postmenopausal endometrium has been typified as atrophic, which is indeed true, but is also implied as being inactive, which in fact it is not; in most cases, the postmenopausal endometrium appears to be weakly proliferative with potential to give rise to an endometrial carcinoma. It is also assumed that postmenopausal endometrial tumours are predominantly of serous papillary and clear cell type, and, in general, they are not well-differentiated endometrioid carcinomas; in reality, no more than 15% are serous papillary and clear cell carcinomas, and no less than 55% are well-differentiated endometrioid neoplasms. The overall prognosis is presumed to be poor, yet postmenopausal patients harbouring well-differentiated endometrioid carcinomas have the same excellent prognosis as those premenopausal women having endometrioid tumours of similar grade and stage. This brief account of endometrial carcinogenesis at menopause re-evaluates these issues and, in the light of new and old evidence, proposes the separation of G1 endometrioid adenocarcinomas (low-grade tumours) from all others (high-grade tumours).

Complications associated with equine castration are the most common cause of malpractice claims against equine practitioners in North America. An understanding of the embryological development and surgical anatomy is essential to differentiate abnormal from normal structures and to minimise complications. Castration of the normal horse can be performed using sedation and regional anaesthesia while the horse is standing, or under general anaesthesia when it is recumbent. Castration of cryptorchid horses is best performed under general anaesthesia at a surgical facility. Techniques for castration include open, closed and half-closed techniques. Failure of left and right testicles to descend occurs with nearly equal frequency, however, the left testicle is found in the abdomen in 75% of cryptorchid horses compared to 42% of right testicles. Bilateral cryptorchid and monorchid horses are uncommon. Surgical approaches described for the castration of cryptorchid horses include an inguinal approach with or without retrieval of the scrotal ligament, a parainguinal approach, or less commonly a suprapubic paramedian or flank approach. Laparoscopic castration of cryptorchid horses has recently been described but the technique has limited application in practice at this time. A definitive diagnosis of monorchidism can only be made after surgical exploration of the abdomen, removal of the normal testis and hormonal testing. Hormonal assays reported to be useful include analysis of basal plasma or serum testosterone or oestrone sulphate concentrations, testosterone concentrations following hCG stimulation, and faecal oestrone sulphate concentrations. Reported complications of castration include postoperative swelling, excessive haemorrhage, eventration, funiculitis, peritonitis, hydrocele, penile damage and continued stallion-like behaviour.

OBJECTIVE

Substantial differences in plasma oestrogen disposition have been reported between Japanese and Caucasian women, but there are currently few data available on the relative endocrinological effects of aromatase inhibitors in these two groups. Hence, the effects of the nonsteroidal aromatase inhibitor anastrozole on serum oestrogen concentrations were compared in 24 healthy postmenopausal Japanese women and 24 healthy postmenopausal Caucasian women.

METHODS

Anastrozole, 1 mg/day, was given once daily for 16 days. Serum oestradiol and oestrone sulphate levels were measured on three consecutive days beginning 2 days before the first dose, and on a further three consecutive days beginning on the penultimate day of dosing. Trough concentrations of anastrozole (measured 24 h after dosing) were also determined during the same periods.

RESULTS

There were no substantial differences in plasma oestrogen concentrations between the Japanese and Caucasian women at baseline. On average, anastrozole suppressed serum oestradiol and oestrone sulphate levels by approximately 87% and 93%, respectively, for both Japanese and Caucasian women, and minimum plasma anastrozole concentrations at steady-state (anastrozole C(min)) were also similar in both groups. Statistical analysis of serum oestradiol and serum oestrone sulphate levels, and plasma anastrozole C(min) showed that there were no statistically significant differences between the Japanese and Caucasian women.

CONCLUSIONS

Neither the pharmacodynamic effects of anastrozole on serum oestrogens nor the pharmacokinetics of anastrozole differ between postmenopausal Japanese and Caucasian women. Hence, these findings suggest that the therapeutic benefits of anastrozole in Caucasians will be predictive of the drug's effect in Japanese women and support the use of anastrozole in postmenopausal Japanese women with breast cancer.

Intratumoral levels of E1 (oestrone), E1S (oestrone sulphate) and E2 (oestradiol) are significantly reduced by treatment with the aromatase inhibitor anastrozole regardless of treatment response. The purpose of the present pilot study was to look for additional markers of biochemical response to aromatase inhibitors on mRNA expression level. Whole genome expression was studied using microarray analysis of breast cancer tissue from 12 patients with locally advanced tumors, both before and following 15 weeks of treatment with the aromatase inhibitor anastrozole (Arimidex). Intratumoral mRNA levels for a subset of genes coding for steroid metabolizing enzymes, hormone receptors and some growth mediators involved in cell cycle control were analysed by quantitative RT-PCR. There was a correlation between the two methods for some but not all genes. The mRNA expression levels of the different genes were correlated to each other and to the intratumoral levels of E1, E2 and E1S, before and after the treatment. Notably, a correlation of the E1/E2 metabolic ratio to the mRNA levels of CYP19A1 was observed before treatment (r=0.745, p<0.005). Whole genome expression analysis of these 12 breast cancer patients revealed similar tumor classification to previously published larger studies. Tumors with no or low expression of ESR1 (oestrogen receptor) clustered together and were characterized by a strong basal-like signature highly expressing keratins 5/17, cadherin 3, frizzled and apolipoprotein D, among others. The luminal epithelial tumor cluster, on the other hand, highly expressed ESR1, GATA binding protein 3 and N-acetyl transferase. An evident ERBB2 cluster was observed due to the marked over-expression of the ERBB2 gene and GRB7 and PPARBP in this patient material). Using significance analysis of microarrays (SAM), we identified 298 genes significantly differently expressed between the partial response and progressive disease groups.

This study aimed to describe the association between incidence of boar taint and pubertal changes in gonadal hormones, size of reproductive organs and aggressive behaviour in entire male pigs. In total, 111 entire male pigs were included in the study. Sampling was performed first at 90 kg live weight (LW) and, then, at 115 kg LW. Variables measured were skatole and androstenone levels in plasma and fat, testosterone and oestrone sulphate in plasma, free oestrone in fat, weight of testes and length of bulbourethral glands. Aggressive interactions between pigs were registered when a limited amount of feed was provided to the pigs prior to routine feeding. The number of initiated interactions (attacks) and the difference between number of initiated and received interactions (relative attacks) were calculated for each pig. Multivariate analysis revealed that gonadal hormones and reproductive organ size influenced prevalence of boar taint, accounting for 30% of the variation in skatole levels in fat and for 37% of the variation in androstenone levels in fat. These relations were independent of aggression levels in entire male pigs. Skatole levels were influenced by the levels of oestrone sulphate in plasma and free oestrone in fat, but not levels of plasma testosterone. Pigs with testes weight below 565 g and a bulbourethral gland length <90 mm did not produce high amounts of skatole; therefore, these values can be used as a threshold level to detect pig carcasses with low skatole levels. High androstenone levels could not be predicted by measuring reproductive organ sizes. More research is required to develop a rapid and accurate method for the analysis of carcasses of entire male pigs.