The sulphatase pathway is thought to be the major route of oestrogen synthesis in breast tumours in postmenopausal women. There is currently considerable interest in developing a potent steroid sulphatase inhibitor to block oestrogen synthesis by this route. One of the most potent inhibitors discovered so far is oestrone-3-O-sulphamate (EMATE) which is active in vivo. In this study we report the preparation of a formulation for the administration of EMATE by the oral route. A method, using high-performance liquid chromatography (HPLC), was also established to measure concentrations of EMATE in rat plasma after its oral or i.v. administration. Using the oral formulation and HPLC assay, EMATE was readily detected in rat plasma after oral administration. Plasma EMATE concentrations were related to the dose of drug administered orally over the 10-40 mg/kg range. To examine the pharmacokinetics of EMATE, the compound (40 mg/kg, single dose) was administered either orally (in the formulation) or i.v. (in propylene glycol) with plasma samples being collected for up to 6 h. After oral administration, EMATE was rapidly absorbed, with the peak plasma concentration being detected at 30 min, after which plasma concentrations rapidly decreased. After i.v. administration a plasma EMATE concentration was detected at 1 h similar to that after oral administration. The clearance of EMATE from plasma followed a bi-phasic curve, showing an initial half-life of 30 min, followed by a slower half-life of 4 h 30 min. Little evidence was obtained for any metabolism of EMATE to oestrone. Rat liver sulphatase activity was almost completely inhibited (>99%) within 30 min of oral or i.v. administration of EMATE.

The interconversion of tritium labelled oestrone and oestradiol-17β has been investigated in human breast tumours maintained in organ culture for 3 days. Benign tumours were significantly different from scirrhous carcinomata both in the concentration of radioactivity taken up by the tissue and in the ratios of oestradiol-17β/oestrone achieved. The fact that malignant tumours were able to convert oestrone to oestradiol-17β is of interest in view of the relatively high plasma levels of oestrone in post-menopausal women.

Formation of oestrone via the sulphatase pathway is considered to be a major source of the oestrogen present in breast tumours. Several inhibitors of steroid sulphatase have now been developed for use in the treatment of postmenopausal women with breast cancer. In order to be able to monitor the extent and duration of the inhibition of oestrone sulphatase (E1-STS) readily, we have developed a method to measure the activity of this enzyme in white blood cells (WBCs). Hydrolysis of oestrone sulphate by E1-STS in WBCs was linear with respect to time and the volume of WBCs used. To examine whether the extent of inhibition of E1-STS activity in WBCs, by the inhibitor oestrone-3-O-sulphamate (EMATE), reflected inhibition in other body tissues, activity in WBCs was compared with that in liver and spleen tissue samples from rats. Two hours after an oral dose of EMATE the extent of inhibition of E1-STS detected in WBCs was the same as in the liver. The duration of the inhibition of E1-STS by EMATE, examined over a 1-28 day period in rats, was similar whether monitored in WBCs, liver or spleen. Measurements of E1-STS activity in WBCs were also used to examine the effectiveness of EMATE (0.5 mg/kg) in two male volunteers. E1-STS activity was rapidly inhibited and had only recovered by 27% after 1 month. A marked decrease in the ratio of plasma dehydroepiandrosterone:dehydroepiandrosterone-sulphate (DHA:DHA-S) concentrations was also detected, confirming that EMATE also inhibits DHA-STS activity. The ability to monitor the extent and duration of steroid sulphatase inhibition in WBCs will facilitate the evaluation of this new form of endocrine therapy in women with breast cancer.

We have investigated whether progestins may be able to regulate breast cell proliferation by altering the fraction of oestradiol relative to oestrone, using the human breast cancer cell line MCF-7. The ability of the two oestrogens, oestradiol and oestrone, to stimulate breast tumour cell proliferation was investigated. Oestradiol in concentration was of 10-fold greater proliferative potency than oestrone. The progestin MPA increased both reductive and oxidative 17 beta-hydroxysteroid oxidoreductase activity when the tissue culture media pH indicator phenol red was included in the media. When phenol red was excluded from the tissue culture media, MPA increased predominantly the reductive 17 beta-hydroxysteroid oxidoreductase activity, and to a far greater extent than in the presence of phenol red. Other progestins such as levonorgestrel, norethisterone and norethisterone acetate also increased predominantly reductive 17 beta-hydroxysteroid oxidoreductase activity in the absence of phenol red. The action of MPA on reductive 17 beta-hydroxysteroid oxidoreductase activity was increased by treatment with oestradiol to a small but significant extent. We propose that the progestational increase of reductive 17 beta-hydroxysteroid oxidoreductase activity is a possible mechanism by which progestins may increase breast cell proliferation in vivo.

The potential effects of pesticides and their metabolites on the endocrine system are of major concern to wildlife and human health. In this context, the azole pesticides have earned special attention due to their cytochrome P450 aromatase inhibition potential. Cytochrome P450 aromatase (CYP19) catalyses the conversion of androstenedione and testosterone into oestrone and oestradiol, respectively. Thus, aromatase modulates the oestrogenic balance essential not only for females, but also for male physiology, including gonadal function. Its inhibition affects reproductive organs, fertility and sexual behaviour in humans and wildlife species. Several studies have shown that azole pesticides are able to inhibit human and fish aromatases but the information on birds is lacking. Consequently, it appeared to be of interest to estimate the aromatase inhibition of azoles in three different avian species, namely Gallus gallus, Coturnix coturnix japonica and Taeniopygia guttata. In the absence of the crystal structure of the aromatase enzyme in these bird species, homology models for the individual avian species were constructed using the crystal structure of human aromatase (hAr) (pdb: 3EQM) that showed high sequence similarity for G. gallus (82.0%), T. guttata (81.9%) and C. japonica (81.2%). A homology model with Oncorhynchus mykiss (81.9%) was also designed for comparison purpose. The homology-modelled aromatase for each avian and fish species and crystal structure of human aromatase were selected for docking 46 structurally diverse azoles and related compounds. We showed that the docking behaviour of the chemicals on the different aromatases was broadly the same. We also demonstrated that there was an acceptable level of correlation between the binding score values and the available aromatase inhibition data. This means that the homology models derived on bird and fish species can be used to approximate the potential inhibitory effects of azoles on their aromatase.

Incomplete masculinization due to a deficiency of 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD) was investigated in siblings aged 4 years (Case 1) and 12 years (Case 2). Diagnosis was based on increased ratios of androstenedione (A) to testosterone (T) in blood, and impaired reduction of A to T by 17 beta-HSD in vitro in the testes. Impairment was total in Case 2 but partial in Case 1. Case 2 also showed deficient conversion of dehydroepiandrosterone (DHA) to androstenediol and of oestrone to oestradiol by 17 beta-HSD which were normal in Case 1. Oxidation of T to A by 17 beta-HSD and conversion of 17 alpha-hydroxyprogesterone to A by 17,20 desmolase were normal in the testes of both siblings. 3 beta-HSD conversion of DHA to A was normal in Case 1, but markedly increased in Case 2. In contrast to testicular findings, 17 beta-HSD reduction of A to T in genital skin fibroblasts from Case 2 was normal and diagnosis would not have been possible from studies of measurements of this enzyme in skin. The severity of the testicular 17 beta-HSD deficiency in the peripubertal compared with the prepubertal sibling suggests either considerable intra-familial variation in the extent of the enzyme defect or that puberty may aggravate this disorder. The normal reductive action of 17 beta-HSD in skin, despite impaired action in testes, suggests involvement of more than one iso-enzyme.

A LH-releasing hormone (LHRH) analogue was administered to subjects with elevated circulating LH concentrations and elevated androgens (polycystic ovary syndrome, PCO) and also to a control group with normal menstrual rhythm and normal LH and androgens. In both groups circulating LH concentrations were reduced to low and indistinguishable concentrations. Oestradiol, oestrone, androstenedione and testosterone levels were all reduced by treatment in both groups. However, the reduction in androgen concentrations was less marked in the patients with PCO. The oestrogen/androgen ratios remained relatively unaltered, but the testosterone levels remained slightly elevated in the PCO patients after treatment. The results suggest that patients with PCO syndrome show a disorder of androgen metabolism independent of elevated LH concentrations.

Eighteen men (mean age 27, range 18-30 years) treated for Hodgkin's disease with 6-8 courses of MVPP (Mustine, Vinblastine, Procarbazine and Prednisolone) have had Leydig cell function assessed by their steroidogenic responses to stimulation by a single bolus dose of HCG (1000 units intramuscularly). Normal age-matched men (n = 16) acted as controls. Baseline immunoreactive FSH was markedly raised in the patients (mean 18.1 +/- SD 6.9 vs 2.0 +/- 1.5 IU/l, P less than 0.0001) reflecting damage to the germinal epithelium. Immunoreactive LH was also greater in patients (10.3 +/- 3.9 IU/l) than in controls (3.9 +/- 1.9 IU/l, P less than 0.0001). There were no differences between the baseline testosterone, androstenedione, oestradiol, oestrone and sex hormone binding globulin (SHBG) concentrations. The testosterone/SHBG ratios were similar in the two groups and there was no correlation between baseline LH and testosterone concentrations or testosterone/SHBG ratios. Testosterone, androstenedione, oestradiol and oestrone secretion in response to HCG stimulation were similar at 24 h and 96 h in both groups. In order to explain the paradox of elevated immunoreactive LH in the face of normal testicular steroidogenesis in such patients, LH biological activity (B) as well as LH immunoreactivity (I) and FSH and testosterone were estimated in a second similar group of patients (n = 17, mean age 27, range 17-43 years) and in a further age-matched control group (n = 17). Bioactive and immunoreactive LH levels were significantly increased (P less than 0.005 and P less than 0.001, respectively) in the patient group.(ABSTRACT TRUNCATED AT 250 WORDS)

Dehydroepiandrosterone sulphate (DHEAS) is a major adrenal secretory product, particularly in the fetus where it serves as a substrate for oestrogen biosynthesis by the placenta. The enzyme in the adrenal responsible for synthesising DHEAS, hydroxysteroid sulphotransferase (HST), is therefore essential for human development. We have isolated a full-length cDNA clone, encoding human fetal adrenal HST, and constructed a stable cell line expressing it by transfection into V79 Chinese hamster lung fibroblast cells. This cDNA was essentially identical to that isolated from adult human liver, where the role of HST is less well understood. This recombinant cell line allowed determination of the substrate specificity and kinetic properties of this enzyme towards various steroid hormones, and by comparison of these activities with human liver cytosol we have shown that HST is the major sulphotransferase responsible for the sulphation of DHEA, androsterone and pregnenolone in man and that, functionally, the hepatic and adrenal enzymes are very similar. The expressed HST was also active with testosterone, cortisol (although at low levels) and the xenobiotic 17 alpha-ethinyloestradiol, but not with oestrone or 1-naphthol. We have therefore created a valuable resource for the study of this important enzyme.

The Mira River is a Portuguese water body widely known for its wilderness and is advertised as one of the less polluted European rivers. On this presumption, the levels of endocrine-disrupting compounds (EDCs) in Mira waters were never measured. However, because environmentalists have claimed that the Mira could be moderately polluted, a range of 17 EDCs were measured not only at the estuary but also along the river. The targeted EDCs included natural and pharmaceutical oestrogens (17β-oestradiol, oestrone and 17α-ethynylestradiol), industrial/household pollutants (octylphenols, nonylphenols and their monoethoxylates and diethoxylates and bisphenol A), phytoestrogens (formononetin, biochanin A, daidzein, genistein) and the phytosterol sitosterol (SITO). For this propose, waters from six sampling sites were taken every 2 months, over a 1-year period (2011), and analysed by gas chromatography-mass spectrometry. Unexpectedly high levels of oestrogens and of industrial/household pollutants were measured at all sampling sites, including those located inside natural protected areas. Indeed, the annual average sum of EDCs was ≈57 ng/L for oestrogens and ≈1.3 μg/L for industrial/household chemicals. In contrast, the global average levels of phytoestrogens (≈140 ng/L) and of SITO (≈295 ng/L) were lower than those reported worldwide. The EDC concentrations were normalised for ethynylestradiol equivalents (EE2eq). In view of these, the oestrogenic load of the Mira River attained ≈47 ng/L EE2eq. In addition, phosphates were above legal limits at both spring and summer (>1 mg/L). Overall, data show EDCs at toxicant relevant levels in the Mira and stress the need to monitor rivers that are allegedly less polluted.

Serum levels of androstenedione, dehydroepiandrosterone, dehydroepiandrosterone-sulphate, cortisol, oestrone, and oestradiol are studied in 24 normal young women, and variation in basal oestrogen levels is examined in relation to adrenal androgen levels and relative weight. Between subjects no positive correlation is found between adrenal androgen levels or relative weight and basal oestrogen. Within subjects changes in adrenal androgen levels are positively correlated with changes in basal oestrogens. The results suggest that the basal oestrogen setpoint within each individual is unaffected by weight differences in the normal range, while variation about the setpoint within individuals may accompany fluctuations in adrenal androgen levels. This conclusion is discussed in relation to previous suggestions that relative weight, through an effect on extragonadal oestrogen production, may have an influence on female fecundity.

Aromatase activity measured by the incorporation of [3H]androstenedione into unconjugated and conjugated oestrogens was detectable in the equine conceptus during early pregnancy. Activity was substantially higher in yolk sac compared to allantochorion between Days 20 and 52 after ovulation. Oestrone sulphate concentrations in yolk-sac fluid measured by radioimmunoassay increased markedly to reach values of about 3 micrograms/ml at Day 36, approximately 10-fold higher than those in allantoic fluid. Extra-embryonic membranes in a 28-day conceptus all contained aromatase (chorionic girdle greater than trilaminar omphalopleure greater than bilaminar omphalopleure greater than allantochorion), implying that the enzyme complex was present in trophoblast and/or endoderm rather than mesoderm. Aromatase activity in chorionic girdle cells was low before their migration into the endometrium. Endometrial tissue contained substantial sulphotransferase and glucuronidase activity. The ability of the preimplantation equine conceptus to synthesize oestrogens was strikingly similar to that found previously in the pig; in both species the allantochorionic placenta is non-invasive.

Microsomal fractions isolated from post-partum ovine placentae catalysed the synthesis of [3H]oestrone and [3H]oestradiol from [3H]17alpha-hydroxyprogesterone and NADPH; oestrone and oestradiol were formed in a ratio of approximately 50:1. The expected intermediate, [3H]androstenedione, did not accumulate during these incubations but was shown by trapping experiments to be the intermediate involved. Mean (+/- s.d.) uields of [3H]oestrone (% conversion of substrate) during incubation for 1 h of placentae from five animals in late pregnancy before the onset of labour, from five animals which delivered spontaneously at term and from four animals in which labour was induced by administration dexamethasone to the foetus were: in tissue obtained before labour, 3-2+/-0-44; in tissue obtained after the spontaneous onset of labour, 20-6+/-10-2 (P less than 0-01) and in tissue obtained after dexamethasone-induced labour, 24-4+/-2-13 (P less than 0-0001). This increase in oestrone synthesis suggests activation of steroid C-17,20 lyase, since this is the step limiting the rate of synthesis of oestrone in vitro. The enzyme is probably activated by foetal glucocorticoid. The findings are discussed in relation to the site of synthesis of oestrogens which in the sheep increase in concentration in the peripheral circulation at term, and with reference to a possible mechanism by which foetal glucocorticoid may control the onset of labour in this species.

BACKGROUND

Peripheral conversion of androgens to oestrogens via aromatase is the primary source of oestrogen in postmenopausal women and may play a role in cardiovascular health.

METHODS

Prospective. PARTICIPANTS, MEASUREMENTS: The association of an index of aromatase activity (AROM), the serum oestrone-to-androstenedione ratio, with 25-year cardiovascular disease (CVD) mortality was examined in 819 postmenopausal non-oestrogen using women (mean age at baseline = 72).

RESULTS

Overall, 247 deaths were attributed to CVD. The median AROM value was 60 (95% range 17-129). AROM was positively correlated with age (r = 0·28) and body mass index (BMI) (r = 0·22) (P < 0·001). The age-adjusted risk for CVD mortality was significantly elevated for women in the lowest (HR = 2·01, 95% CI 1·31-3·12) and highest (HR = 1·51, 95%CI 1·02-2·22) quintiles of AROM, compared with the middle quintile. This U-shaped association persisted after additional adjustment for BMI, waist-to-hip ratio, exercise, smoking, alcohol use and traditional CVD risk factor covariates. There was a significant interaction of AROM and BMI (P = 0·001), such that high AROM was associated with a 63% reduction in risk of CVD death for women with low BMI (<22 kg/m(2) ), but with 2·1- to 2·5-fold increased risk in women with mid-range (22-<25 kg/m(2) ) and high (≥25 kg/m(2) ) BMI. Oestradiol did not influence AROM associations and was not independently related to CVD death.

CONCLUSIONS

These results suggest that aromatase is a novel endocrine factor predictive of CVD mortality among postmenopausal women. If confirmed, additional studies are needed to determine whether extremes of aromatase reflect genetic influences or underlying disease processes.

1. Plasma androstenedione, plasma oestrone and the conversion of plasma androstenedione into oestrone were measured in 19 post-menopausal women without fractures (six of them oophorectomized) and 18 with vertebral or femoral neck fractures (four of them oophorectomized). 2. In the series as a whole, the main determinant of the plasma oestrone level was the plasma androstenedione concentration. Only in the small oophorectomized group did the variation in conversion rate make a significant contribution to the variation in plasma oestrone. 3. The conversion rates were not different as between non-fracture and fracture cases but the mean plasma androstenedione and oestrone concentrations were lower (though not significantly) in the latter.

Suicide substrates of aromatase were used as chemical probes to determine if free 19-hydroxyandrost-4-ene-3,17-dione (19-OHA) and 19-oxoandrost-4-ene-3,17-dione (19-oxoA) are obligatory intermediates in the aromatization of androst-4-ene-3,17-dione (androstenedione) to oestrone by human placental aromatase. A radiometric-HPLC assay was used to monitor 19-hydroxy, 19-oxo-, and aromatized products formed in incubations of [14C]androstenedione and human placental microsomes. When microsomes were preincubated with the suicide substrates 10 beta-mercapto-estr-4-ene-3,17-dione (10 beta-SHnorA), or 17 beta-hydroxy-10 beta-mercaptoestr-4-ene-3-one (10 beta-SHnorT), it was found that 19-hydroxy-, 19-oxo- and aromatase activities were inhibited in parallel. However, when the suicide substrates 4-hydroxyandrost-4-ene-3,17-dione (4-OHA) and 19-mercaptoandrost-4-ene-3,17-dione (19-SHA) were preincubated with placental microsomes, significantly greater inhibition of formation of oestrogens was observed in comparison to the inhibition of formation of 19-hydroxy- and 19-oxo-metabolites. Furthermore, significantly more time-dependent inhibition of 19-oxoA formation was observed in comparison to inhibition of 19-OHA formation with these same inhibitors. These results suggest that 19-hydroxy- and 19-oxo-androstenediones are not free, obligatory intermediates in the aromatization of androstenedione by human placental aromatase, but rather are products of their own autonomous cytochrome P-450-dependent, microsomal enzymatic activities.

The biliary excretion of steroid after administration of [3H]oestrone ([3H]E1), [3H]oestrone glucuronide ([3H]E1G) and [3H]oestrone sulphate ([3H]E1S) into the hepatic portal vein of anaesthetized rats was very rapid with more than 70% of E1S and greater than 80% of E1 and E1G excreted in the first 30 min. There was a lag period in the biliary excretion of E1S, this was less apparent with E1 and absent with E1G. Biliary excretion accurately reflects the amount of steroid in the portal circulation and was therefore used as an assessment of absorption from the gastrointestinal (GI) tract. Absorption (as judged by excretion in bile) was least after administration of each steroid into the stomach. The extent of absorption correlated well with the lipophilicity of the steroids as shown by their relative partition coefficients between n-octanol and pH 6.5 phosphate-buffered saline (E1 greater than or equal to E1S greater than or equal to E1G). There was no significant difference in excretion profile when the steroids were given into the caecum (at 5 h, E1, 46.3 +/- 9.1%; E1G, 42.2 +/- 14.5%; E1S, 39.9 +/- 7.1%). The similarity, despite marked differences in physicochemical properties, suggested conjugate hydrolysis to the parent steroid. In contrast, after administration into the small intestine, excretion of E1 was very rapid and was maximal at 1 h (72.5 +/- 8.0%); E1G showed a near-linear excretion rate (1 h, 14.4 +/- 3.0%; 5 h, 80.0 +/- 11.7%), whereas in comparison E1S excretion was low (1 h, 12.1 +/- 2.4%; 5 h, 36.9 +/- 2.7%). The involvement of hydrolytic enzymes in conjugate absorption was assessed. Ampicillin pretreatment (200 mg/kg/day for 2 days) reduced the absorption of E1G from both the proximal and distal small intestine (by approximately 50%) but had no effect on the absorption of E1S. There was, therefore, evidence that quantitative absorption of E1G requires prior hydrolysis (by mammalian and/or microbial enzymes) but intact absorption of E1S from this region of the tract was implicated. Ampicillin pretreatment reduced the absorption of both conjugates (greater with E1S) from the caecum; hydrolysis clearly precedes absorption from the caecum. The above findings were supported by an in vitro study which showed that ampicillin pretreatment abolished the hydrolysis of E1S by caecal contents but only partially reduced the hydrolysis of E1G. The presence of mammalian glucuronidase enzyme may account for this difference.

Group housing of sows during the mating and gestation period has become the overall common management practice in Sweden. Loose housing is probably less stressful for the animals because it allows them more opportunities to behave naturally, but mixing unfamiliar sows does create a stressful situation due to aggressive interactions, which can lead to food deprivation. The objective of the present study was to investigate and compare the effects of stress in form of food deprivation and ACTH administration at days 13 and 14 of pregnancy (day 1, first day of standing oestrus) in sows. The hormonal secretion of the sows and foetal survival by day 30 of pregnancy was, therefore, studied in 17 crossbred multiparous sows. The sows were randomly allocated into three different groups: one control (C-) group; one food deprived (FD-) group, which was deprived of food from the morning of day 13 of pregnancy until the evening meal on day 14; and a third group (A-), which was given intravenous injections of synthetic ACTH (Synachten Depot), at a dose of 0.01 mg/kg body weight every sixth hour from 6 a.m. on day 13 until 6 a.m. on day 15 of pregnancy. All sows were slaughtered at 30 +/- 2 day of pregnancy and the genital tracts recovered. Total number of corpora lutea (CL), total number of viable or nonviable embryos and foetal survival rates were determined. Samples from the peripheral blood circulation were collected four times a day from day 12 until slaughter, except during days 13-15 when blood was collected every second hour. The blood samples were analysed for cortisol, progesterone, oestrone, prostaglandin F(2alpha)-metabolite, oestrone-sulphate, insulin, free fatty acids and triglycerides. FD-sows had increased levels of cortisol, free fatty acids and progesterone, as well as a lowered level of insulin in the peripheral blood plasma, while A-group sows had increased levels of both cortisol and insulin compared with the C-group. Treatment with ACTH seemed to cause a 2-day delay in the increase of oestrone, from day 19, as seen in the FD- and C-group, to day 21 of pregnancy. At the time of slaughter, there were no significant differences among groups in terms of total number of foetuses and foetal survival rate. The results of the present study suggest a capacity of the sow to compensate for the influence of induced moderate stress at the time of pregnancy when maternal recognition occurs.

The metabolism of [4-(14)C]oestrone and of [6,7-(3)H(2)]oestrone sulphate was studied during cyclic perfusion and once-through perfusion of the isolated rat liver. The following results were obtained. 1. As shown by once-through perfusion, the two steroids are metabolized differently during the first passage through the organ. [4-(14)C]Oestrone was taken up by the liver and partly delivered as oestradiol-17beta and oestriol into the medium. After uptake of [6,7-(3)H(2)]oestrone sulphate, only oestrone, liberated by hydrolysis, was delivered into the medium; no oestradiol-17beta or oestriol could be detected in the medium after one passage through the organ. This indicates that intracellular oestrone, which was taken up as such, and oestrone, which derived from intracellular hydrolysis, may be metabolized in different compartments of the liver cell. 2. The results of the cyclic perfusion showed that intracellular oestrone is preferentially conjugated with glucuronic acid, and subsequently excreted into the bile. Intracellular oestrone sulphate is preferably reduced to oestradiol sulphate, thus indicating that oestrone sulphate is a better substrate for the 17beta-hydroxy steroid oxidoreductase than is oestrone. 3. Albumin-bound oestrone sulphate acts as a large reservoir, and in contrast with free oestrone is protected from enzyme attack by its strong binding to albumin. 4. Oestrone sulphate is partly converted into the hormonally active oestrone by liver tissue. This suggests that liver not only inactivates oestrogens, but also provides the organism with oestrone, which is subsequently readily taken up by other organs.

Indomethacin administration in late pregnancy prolonged gestation in caged rhesus monkeys and inhibited premature labour and postponed delivery in chronically catheterized monkey fetuses. Chronic indomethacin treatment was associated with a reduction in the urinary excretion of a prostaglandin metabolite, a potent inhibitory effect on myometrial cyclic AMP phosphodiesterase, and severe oligohydramnios in pre-term and post-term fetuses. Experimental anencephaly (functional hypophysectomy) of the rhesus fetus results in lowered concentrations of maternal oestradiol and loss of the precise control of gestational length, with 40% of fetuses delivering beyond term. Corticotropin (ACTH) infused into the fetus results in raised concentrations of fetal and maternal cortisol, progesterone and oestrogens. Progesterone concentrations in peripheral blood apparently have little bearing on uterine quiescence in the rhesus monkey, since the concentrations of progesterone in maternal and fetal blood vary directly with uterine activity. The results of chronic infusion of corticotropin in the fetal monkey support the theory that in the monkey parturition is mediated by increased oestrogen production by the fetoplacental unit and by a rise in the concentrations of oestrone and prostaglandin in the amniotic fluid.

This study presents serum concentrations of pregnancy-associated glycoprotein (PAG), oestrone sulphate (E1-S) and progesterone (P4), and the effects of some dam and foetus-related factors on these profiles during gestation in Borana and crossbred cattle. The PAG concentrations at 4th week post-conception ranged from 1.5-5.5 and 2.1-4.7 ng/ml in Borana (n = 6) and crossbred (n = 8) cattle, respectively. The mean PAG concentrations increased progressively from 4th to 33rd week of gestation (from 3.3-173 ng/ml for Borana and 4.2-240 ng/ml for crossbred cattle) and reached peak around calving. Breed, parity status, dam body weight, foetal sex and foetal birth weight significantly influenced the PAG concentrations. After delivery, the PAG concentrations declined steadily to 5.7 ng/ml in Borana (n = 7) and 3.9 ng/ml in crossbred (n = 6) cattle 10 weeks post-partum. The serum E1-S concentrations at 17th week of pregnancy ranged from 0.3-2.6 and 0.9-5.7 ng/ml in Borana (n = 8) and crossbred (n = 9) cattle, respectively. The mean E1-S concentrations increased progressively from 17th to 33rd week of gestation (from 1.1-4.6 ng/ml for Borana and 2.7-10.8 ng/ml for crossbred). Breed, parity status, dam body weight and foetal sex significantly influenced E1-S concentrations. The P4 concentrations at 4th week of pregnancy ranged from 3.2-5.1 and 1.7-8.9 ng/ml in Borana (n = 6) and crossbred (n = 8) cattle, respectively. The P4 level remained elevated throughout pregnancy. This study indicated that the serum PAG and P4 concentrations at 4th and E1-S approximately 17th week of pregnancy were above the cut-off value for pregnancy test and the hormonal profiles observed were comparable to the previous reports. Furthermore, the PAG and E1-S profiles were considerably influenced by factors such as breed, weight and parity status of the dam, and foetal sex and foetal birth weight (only PAG).

Earlier studies have shown that polychlorinated biphenyls (PCB) do not prevent ovulation, fertilization and implantation, but exposure of female mink during gestation caused fetal death. To understand this phenomenon, 30 PCB-exposed female mink and 30 controls were mated or induced to ovulate without fertilization by treatment with gonadotrophin-releasing hormone (GnRH) and correlations were measured between reproductive, morphological and endocrine parameters. The exposure to PCB (Aroclor 1254) started before ovulation. Equal numbers of animals from each group were killed on days 10, 17 and 26 post-coitum or on GnRH-injection days. Plasma concentrations of progesterone, oestradiol-17beta and oestrone sulphate in sampled blood were then measured. Ovaries, uteri and placentae were examined histologically. Compared with controls, exposure to PCB during the reproductive season resulted in significantly smaller uterine glandular diameters before implantation or at the end of the experiment in both mated and GnRH-treated mink. The GnRH treatment increased the sizes of the ovarian corpora lutea and oesterone sulphate 10 days after treatment but the increase in uterine glandular diameter was significant only in GnRH-treated control animals. Both GnRH-treated and mated PCB-exposed groups displayed a peak in oesterone sulphate concentration that was not observed in any of the control groups. Possible actions of PCB are discussed. The observed histological and hormonal changes in the mated PCB-exposed group did not prevent implantation. Exposure to PCB increased fetal mortality. This effect was associated with an effect on placental development.

Menstrual blood was collected from five eumenorrheic and seven dysmenorrheic women aged between 20 and 35 years for a period of three cycles each. The levels of prostaglandin F2 alpha (PGF2 alpha), prostaglandin E2 (PGE2), 6-keto-prostaglandin F1 alpha (6-k-PGF1 alpha)-the stable metabolite of prostacyclin (PGI2)-, oestradiol, oestrone, and progesterone were determined radioimmunologically. Both eumenorrheic and dysmenorrheic women showed identical blood losses. The levels of oestradiol excreted by the dysmenorrheic women were markedly elevated as compared to the non-dysmenorrheic subjects (2 p less than 0.05). Oestrone excretion was in the same order of magnitude in all subjects examined. The concentration of progesterone per menstruation was significantly higher in the eumenorrheic women (2 p less than 0.02) than in the dysmenorrheic patients. Menstrual excretion of PGF2 alpha was 2.5 times higher in the dysmenorrheic women compared to the normal subjects (2 p less than 0.05). The levels of PGE2 was identical in both groups. Excretion of 6-k-PGF1 alpha was significantly lower in the dysmenorrheic women than in the eumenorrheic subjects (2 p less than 0.02). The oestradiol/progesterone ratio showed a distinct predominance of oestradiol in the dysmenorrheic patients. PGF2 alpha dominance in the dysmenorrheic patients is expressed by the PGF2 alpha/6-k-PGF1 alpha and the PGF2 alpha/PGE2 ratios. A shift in the oestradiol/progesterone ratio in favour of oestradiol seems to be the underlying pathogenic principle of dysmenorrhea. The oestradiol dominance is associated with a shift in the PGF2 alpha/PGI2 and the PGF2 alpha/PGE2 proportions. Thus, the PGF2 alpha predominance and a simultaneous reduction of PGI2 in uterine tissue seem to be responsible for dysmenorrheic bleeding.