Equivalent doses of oestradiol-17 beta were given orally and percutaneously to eight post-menopausal women and three men. The resultant serum levels of unconjugated immunoreactive oestrogens and total oestrone were followed during 48 hours after hormone administration. A single percutaneous dose of 4 mg oestradiol-17 beta resulted in increased serum levels of oestradiol-17 beta in all individuals. Compared to oral administration the increase in serum oestrogen levels was quite slow and they were maintained for 48 hours. In contrast to the rapid and very marked increase in serum total oestrone following oral administration of oestradiol-17 beta, only a moderate increase was obtained after percutaneous administration and there was a tendency to a biphasic pattern. Topical administration of oestradiol-17 beta might have physiological advantages as the steroid will reach the peripheral circulation without passing the entero-hepatic circulation.

Oestradiol (E2), oestriol (E3) and oestrone (E1) levels were measured in plasma and endometrium, myometrium and vagina of 29 postmenopausal women who underwent hysterectomy. The influence of vaginal E3, compared to vaginal E2 therapy at a dose one-tenth that of E3 on the basal steroid levels was examined. We found (1) no correlation between basal tissue and plasma concentrations of the oestrogens in untreated postmenopausal women, however, after vaginal E3 therapy we did find a positive correlation between them, (2) E2 to be the oestrogen in the highest basal concentration in endometrium and myometrium as well as in the vagina, (3) higher basal concentrations of all three oestrogens in endometrium compared to myometrium and vagina, (4) a long term (at least 12 h) elevation of the plasma and tissue E3 concentrations after vaginal E3 therapy (0.5 mg per day), (5) no significant changes of the plasma and tissue E2 concentrations after 0.05 mg per day vaginal E2 therapy, measured 12 h after the last application and (6) no signs of a difference between vagina and uterus in uptake and retention of E3 or E2. In conclusion, there was no difference on this level of mechanism of action in vagina and uterus which can account for the supposed vaginotrophicity and non-uterotrophicity observed with E3 but not E2.

During pregnancy in goats the concentration of endogenous oestrone sulphate in milk increased more than twofold, and that in arterial and mammary venous plasma 10- and 20-fold respectively. The concentration in milk was higher than that in arterial plasma, particularly in lactating goats during mid-gestation. This was partly related to mammary production of oestrone sulphate (or of a closely related steroid which cross-reacted in the radioimmunoassay) since in tracer infusion studies the specific activity of oestrone sulphate in milk was significantly lower than that in arterial or mammary venous plasma. It was also related to the existence of a mechanism within the gland which concentrates oestrone sulphate in milk since when infused close-arterially into the mammary gland of a non-pregnant goat with undetectable levels of the endogenous compound in the circulation, a concentration ratio of 7.4:1.0 was reached for oestrone sulphate in milk:arterial plasma. Tracer kinetic studies showed that mammary extraction of [3H]oestrone sulphate was variable (up to 41.3 +/- 30.6%, mean +/- S.E.M.). During intravenous or close-arterial infusion, radioactivity in arterial and mammary venous plasma at steady state was mainly in the form of [3H]oestrone sulphate (range, 64 +/- 10.6 to 80.2 +/- 5.9% of total radioactivity in plasma). The remainder was in the form of compounds chromatographically similar to oestradiol-17 beta-3-monosulphate, oestradiol-17 alpha-3-monosulphate and unconjugated oestrogens. The distribution of radioactivity between these different steriods was similar in arterial mammary venous plasma indicating a low level of selective mammary metabolism or extraction. The amount of labelled oestrone sulphate transferred into milk was low, and it was significantly less in pregnant (range, 0.11 +/- 0.07 to 0.27 +/- 0.16% of total infusate) than in non-pregnant animals (3.23 +/- 0.50%). Studies of the rate of transfer of [3H]oestrone sulphate from blood to milk indicated the presence of a transcellular route with peak activity in milk occurring about 110 min after the start of the infusion.

Urinary excretion of oestrone conjugates, pregnanediol-3 alpha-glucuronide (PdG) and 20 alpha-hydroxypregn-4-en-3-one were measured from 8 weeks before oestrus to 2 weeks post partum and bioactive FSH was monitored during the periovulatory interval in a female giant panda. A biphasic urinary bioactive FSH excretory profile appeared to indicate a broad (approximately 10 day) follicular phase followed by a sharp preovulatory bioactive FSH surge coincident with an acute increase in urinary oestrone conjugates and behavioural oestrus. Weekly concentrations of urinary oestrone conjugates and PdG increased (P less than 0.001) by Week 9 of gestation with 20 alpha-hydroxypregn-4-en-3-one levels increasing 10-30-fold (P less than 0.001) between Weeks 11 and 14. These observations indicate that the monoestrous giant panda does not appear to require a prolonged period of endogenous FSH release or multiple FSH peaks for ovarian priming and follicle selection to proceed normally. Furthermore, the delayed rise in urinary steroid excretion during the second half of gestation in the giant panda supports the concept of delayed implantation while the estimation of steroid conjugates in urine offers a non-invasive approach for monitoring pregnancy status in this endangered species.

Oestrogen-progesterone imbalance in favour of the oestrogens is considered to be an important factor in the development of mammary cancer, although oestrogens are not directly mitogenic. Moreover, this promoter effect of carcinogenesis may be limited in time. Except for increased plasma (free) oestradiol levels, plasma sex hormone levels in breast cancer patients are comparable to those in normal women, matched for age and weight. In both benign and malignant breast tissue, sex hormone concentrations (ng/g) are significantly higher than in plasma (ng/mg), except for dehydroepiandrosterone sulphate, oestrone sulphate and testosterone, but in breast cancer tissues, dehydroepiandrosterone sulphate (DHEAS), 5 alpha-androstane-3 alpha-17 beta-diol and progesterone concentrations are lower than in normal breast tissue. As to the origin of these sex hormones in breast tissue, a positive arteriovenous gradient across the breast tissue has been observed for androstenedione and oestradiol, suggesting uptake from plasma by the tissues. Aromatization of androstenedione, on the other hand, is probably only a minor source of oestrogens in breast tissue. Hydrolysis of oestrone sulphate taken up from the blood, or oestradiol-17 beta fatty acid esters may be another source, but data are too scarce at present to draw a final conclusion as to their role as source of tissue oestrogens. 17 beta-hydroxysteroid dehydrogenase activity, inactivating oestradiol into oestrone, may be an important determinant of tissue oestradiol concentration. This enzyme activity was found to be higher in oestrogen receptor positive than in oestrogen receptor negative tissues and was negatively correlated with DHEA and DHEAS concentrations. As it was shown that the latter two steroids are non-competitive inhibitors of the 17 beta-hydroxysteroid dehydrogenase as well as of the oestrogen-sulphotransferase, it appears that DHEA may be an important modulator of tissue oestradiol concentration, whereas the 17 beta-hydroxysteroid dehydrogenase might constitute an additional marker of hormone dependency of breast cancer.

BACKGROUND

This prospective study compares the characteristics of cystic disease of the breast (CDB) of patients who developed breast cancer (BCa) during the follow-up (1.25-4 years) period with those who did not.

METHODS

K+, Na+, albumin, dehydroepiandrosterone (DHA), DHA-sulphate, oestrone, oestradiol, testosterone and progesterone levels were determined in breast cyst fluid (BCF). Patients presented data about their menstrual status, reproductive history, lactation period, date of first and the number of BCF aspirations, gynaecological interventions, use of oral contraceptives, family history of cancer, smoking habits and coffee consumption. The BCa incidence of patients was compared with the expected number of BCas in an age-matched group of 5143 women.

RESULTS

Out of 147 patients 6 developed BCa. The standardized incidence rate was 6.29. There were significant differences in testosterone, oestrone and progesterone levels and also reproductive history of patients who developed BCa compared with patients without BCa.

CONCLUSIONS

The above markers outline a subgroup of patients with the highest BCa risk.

Renal cortical necrosis was induced by the administration of vasopressin to oestrogen-pretreated rats. Histochemical (succinic dehydrogenase, trichrome, perjod acid Schiff) and electronmicroscopic methods were applied to examine how the vasopressin antagonist d(CH2)5Tyr(Met)AVP influences the development of this renal cortical necrosis. The experiments revealed that vasopressin did not induce hypoxia or necrosis in the renal tubules if the antagonist was administered simultaneously, even after oestrogen pretreatment. The conclusion is drawn that this pressor antagonist may be of value for the prevention of renal cortical necrosis in rats or in human beings.

2-Fluoro-[6,7-3H]17 beta-oestradiol([3H]2-FE2) and 4-fluoro-[6,7-3H]17 beta-oestradiol([3H]4-FE2) were synthesized by the fluorination and reduction of [3H]oestrone and purified by HPLC. [3H]2-FE2 and [3H]4-FE2 (72.5 micrograms/kg; 0.25 mumol/kg) were administered i.v. to anaesthetized female and male Wistar rats (N = 4) with biliary cannulae. Bile was collected for 6 hr. Female rats administered [3H]2-FE2 excreted 85% of the dose into bile over 6 hr whilst male rats excreted 77%. After the administration of [3H]4-FE2, female and male rats excreted 72 and 83% of dose into bile over 6 hr, respectively. The biliary metabolites were glucuronides in all cases. The principal metabolite of [3H]2-FE2 liberated from biliary conjugates by beta-glucuronidase was 2-fluoroestrone in both female rats (64% of dose) and male rats (57%). No 2-hydroxylated, i.e. oxidatively defluorinated, metabolites were detected in either sex. In contrast, 2-hydroxylation of [3H]4-FE2 did occur, but only in female rats: 2-hydroxy-4-fluoro-oestrone (22%) and 2-methoxy-4-fluoroestrone (17%) were identified as biliary aglycones. However, the major metabolite was 4-fluoroestrone (4FE1; 38%). In male rats, 4-FE1 and 4-fluoro D-ring-oxygenated products were the principal biliary aglycones. The differences in metabolism between the two fluoro analogues and oestradiol are discussed with particular reference to the possible involvement of 2- and 4-hydroxy (catechol) oestrogens in oestrogen toxicity.

We have examined factors influencing the rate of first referral to hospital for urinary tract infection among the 17,032 women taking part in the Oxford Family Planning Association contraceptive study. The risk of first referral declined with age, was higher in nulliparous women than in parous women, was higher in non-obese than in obese women and was higher in current users of the diaphragm than in current users of other methods or no method of contraception. The main increase in the risk of referral in current diaphragm users occurred during the first 24 months when overall rates were 2-3 times higher in users than in non-users or ex-users of the diaphragm. The negative association between hospital referral for urinary tract infection and obesity was unexpected. It was not explicable in terms of age, parity or diaphragm use. It may be that obese women are less likely to receive trauma to the genital area during sexual intercourse than non-obese women because adipose tissue offers them some protection. Another possibility is that increased oestrogenization in obese women, resulting from peripheral conversion of androstenedione to oestrone, has a beneficial effect on the bladder and urethra, thus reducing the liability to infection.

Plasma oestrone (E1) and androstenedione (A) were measured in 96 untreated and 18 corticosteroid-treated post-menopausal women. Levels of both hormones were consistently lower in the steroid-treated cases, presumably due to suppression of ACTH secretion. There was a clear relationship between A and E1 levels in both groups and when the data were pooled they formed a continuous series with a curvilinear relationship going through the origin. This relationship could be described by an equation based on Michaelis-Menten kinetics, suggesting that the rate of A to E1 conversion is an inverse function of the plasma androstenedione level. The main determinant of plasma E1 was plasma A; body weight and age were of subsidiary importance. Secondary oestrogen deficiency may be a factor in the genesis of steroid-induced osteoporosis in post-menopausal women and oestrogen therapy may be indicated in this group of patients.

Plasma androstenedione (A) levels and plasma oestrone (E1) levels were measured by radioimmunoassay in a total of 135 healthy women (the control group), around the menopause. Both A and E1 plasma levels were found to drop significantly in the post-menopausal women (P less than 0.001). The mean plasma levels of A and E1 found in these healthy women were compared with the same plasma levels found in a total of 96 hospitalized women who were found to have various gynaecological disorders. Out of the total 96 patients, 29 were post-menopausal and had adenocarcinoma of the endometrium. The mean plasma levels of A and E1 were not significantly different in comparison with the norm. The mean body weight of the tumour patients was slightly higher than the mean body weight of the healthy women. There were 25 other patients, around the menopause, who had glandular hyperplasia of the endometrium. The mean plasma levels of androstenedione found in these women were significantly higher than the mean levels found in the healthy group of women; both groups were similar in body weight. The oestrone levels found in these patients were within the normal range. The remaining 42 patients, around the menopause, were affected with dysfunctional uterine bleeding, without endometrial hyperplasia. The plasma androstenedione levels were within the normal range. Oestrone plasma levels were not measured in this group of women. This study investigates the possible differences found in the endocrine plasma levels of women with glandular hyperplasia and adenocarcinoma of the endometrium.

Plasma androstenedione (A) and oestrone (E1) levels were measured by radioimmunoassay in 45 hospitalized patients who had non-endocrine benign or malignant ovarian tumours or cysts. The findings of these measurements were compared with the findings of the mean steroid levels which we determined previously (see previous article) in 135 healthy women, around the menopause, of similar weight. Of the total number of patients, 26 had non-endocrine benign ovarian tumours and cysts and were in the reproductive and pre-menopausal ages. The mean plasma A level was found to be significantly higher than the normal value (P less than 0.001). However, the plasma E1 level was not different from the norm. The remaining 19 patients, all around the menopause, had non-endocrine malignant epithelial ovarian tumours. The mean plasma levels of both A and E1 were found to be significantly higher (P less than 0.001) than the normal values. Since increased plasma A levels are associated with non-endocrine ovarian tumours and cysts, it seems likely that the measurement of plasma A may be used as an endocrine detector of non-endocrine ovarian tumours.

Unlike in other non-human primates, ovariectomy of the female marmoset did not alter heterosexual interactions. Proceptive behaviour bouts retained the same cyclicity, duration and frequency within tests as during the ovarian cycle. Significant rises in plasma levels of cortisol, progesterone, oestrone and testosterone were found during these proceptive behaviour bouts and in cortisol, progesterone and oestrone at their onset. Results suggest a role for adrenocortical steroids in both maintaining female sexuality and regulating its cyclicity during ovarian cycles in this primate.

OBJECTIVE

Vision depends on retinoid exchange between the retinal pigment epithelium (RPE) and photoreceptors. Defects in any step of the canonical visual cycle can lead to retinal degenerations. All-trans-retinol (atROL) plays an important role in visual signal transduction. However, how atROL enters human RPE from the apical membrane remains unclear. This study investigated the role of human organic anion transporting polypeptide 1A2 (OATP1A2) in atROL uptake in human RPE.

METHODS

Immunoblotting and immunostaining elucidated the expression and localization of OATP1A2 in human RPE. Transporter functional studies were conducted to assess the interaction of OATP1A2 with atROL.

RESULTS

Our study revealed OATP1A2 is expressed in human RPE, mainly at the apical membrane. Our data also indicated atROL inhibited the uptake of the typical OATP1A2 substrate, oestrone-3-sulfate (E3S), in over-expressing cells. Studies on the uptake of (3) H-atROL in these over-expressing cells revealed atROL is a substrate of OATP1A2. We confirmed these findings in human primary RPE cells. The transport of E3S and atROL was significantly reduced in human primary RPE cells with OATP1A2 siRNA silencing.

CONCLUSIONS

Our data provides the first evidence of OATP1A2 expression in human RPE and more importantly, its novel role in the cellular uptake of atROL, which might be essential to the proper functioning of the canonical visual cycle. Our findings contribute to the understanding of the molecular mechanisms involved in retinoid transport between the RPE and photoreceptors and provide novel insights into potential pharmaceutical interventions for visual cycle disruption associated with retinal degenerations.

The growth hormone (GH) response to apomorphine HCl (Apo) (0.75 mg sc), a dopamine (DA) receptor agonist, was assessed in healthy chronic alcoholics without cirrhosis (N = 20) and in patients with alcoholic cirrhosis both with (N = 5) and without (N = 14) hepatic encephalopathy (HE). A significant number of cirrhotic patients with (P less than 0.004) and without (P less than 0.002) HE had an impaired GH response (peak increment less than 5 ng/ml) compared with non-cirrhotic individuals. An impaired GH response was independent of the presence of HE. The magnitude of the GH response was unrelated to plasma oestrone, oestradiol, or progesterone concentrations but was significantly correlated with plasma testosterone levels (P less than 0.01). None of the patients with an abnormally low testosterone concentration showed a normal GH response. None of the subjects with HE showed an arousal response to Apo. These results suggest that DA receptor sensitivity is decreased in liver cirrhosis and that this decrease is related to inadequate circulating levels of testosterone. The occurrence of HE is independent of impaired DA function. The present study only evaluates DA function in the hypothalamic-pituitary axis and therefore may not reflect changes in other regions of brain.

By analogy with combination chemotherapy, endocrine agents with different mechanisms of action have been combined in the treatment of patients with advanced breast cancer. The clinical use of tamoxifen+aminoglutethimide+hydrocortisone showed no clinical benefit over the individual use of tamoxifen or aminoglutethimide+hydrocortisone. The endocrine changes occurring in postmenopausal patients as a consequence of their treatment with tamoxifen+aminoglutethimide+hydrocortisone have been examined. Suppression of gonadotrophin and oestrogen levels and increased levels of sex hormone binding globulin were observed. These changes might be expected to be of benefit in the treatment of advanced breast cancer, and do not explain the lack of clinical benefit in combining the treatments. Non-responders to this combination therapy had higher levels of oestrone and dehydroepiandrosterone sulphate whilst on treatment than responders, confirming previous observations in patients treated with aminoglutethimide+hydrocortisone.

The effects of subcutaneous oestradiol implants on ovarian activity were investigated in 14 ovulating premenopausal women. Treatment with either 100 mg or 150 mg oestradiol was combined with cyclical oral norethisterone from days 20 to 26 of the cycle to ensure regular withdrawal periods and prevent endometrial hyperplasia. Ovarian function was monitored by regular pelvic ultrasonography and urinalysis over a period of nine cycles. During the first three cycles after hormone implantation, follicular development continued in almost half the study group, but only one of the women in each treatment group showed signs of follicular rupture and luteinization. By the sixth cycle, over half the women given the lower dose of oestradiol were developing follicles, including a large functional cyst in one, but none of them ovulated. A further implant given early in the seventh cycle was associated with ovarian suppression in all cases. Both doses of implant elevated the excretion of oestrone-3-glucuronide compared to pretreatment. The contraceptive and therapeutic implications of these results are discussed.

The dissociation constants (Kd) and steroid specificities of oestrogen-binding species in rat granulosa cell cytosol and nuclei have been studied. Preliminary work, where diethylstilboestrol was employed as competitor in binding assays, identified the oestrogen receptor in whole ovarian tissue nuclei (Kd 0.35 +/- 0.09 nmol/l) and cytosol (Kd 0.39 +/- 0.03 nmol/l). Isolation of granulosa cells revealed that the majority of this receptor (75-96%) was present in these cells. Specificity studies on the binding of [3H]oestradiol in granulosa cell cytosol indicated the presence of an additional class of oestrogen-binding sites which were, however, not present in nuclei. Saturation analysis over an extended range of [3H]oestradiol concentrations and using unlabelled oestradiol as competitor revealed a binding species of Kd 45.8 +/- 6.9 nmol/l (capacity 16.7 pmol/mg cytosol protein) for oestradiol in addition to the cytosol oestrogen receptor of Kd 0.58 +/- 0.22 nmol/l (capacity 2.8 pmol/mg cytosol protein). The low affinity of this novel species implies that the dextran-coated charcoal techniques used in previous studies on ovarian oestrogen-binding species would cause dissociation of ligand and not allow it to be measured. The second oestrogen-binding species displayed affinity for oestradiol-17 beta, oestriol, oestrone, testosterone, 5 alpha-dihydrotestosterone, methyltrienolone, progesterone and the antioestrogens tamoxifen, nafoxidine and clomiphene citrate. The species, however, did not bind diethylstilboestrol, a characteristic shared with other low affinity cytosol oestrogen-binding species which have been reported in dog prostate, chick oviduct and male rat liver but not shared with uterine type II oestrogen receptors.(ABSTRACT TRUNCATED AT 250 WORDS)

During short periods of incubation (3 h) the secretion of progesterone by granulosa cells from the largest preovulatory follicle of the fowl was higher (160 pmol/micrograms DNA) with ovine LH in the medium than without it (60 pmol/micrograms DNA). Granulosa cells from follicles collected 24 and 48 h before their expected ovulation secreted progesterone at similar rates to cells from the largest follicle which was likely to ovulate within 5 h. The identity of progesterone was confirmed by physicochemical methods. After granulosa cells had been incubated with LH in Medium 199 for 24 h, the concentration of progesterone in the medium was 1.65 mumol/l whereas oestrone and oestradiol were present at concentrations of 254 and 199 pmol/l respectively. The results indicate that the larger yellow yolk-filled follicles of the ovarian hierarchy in the domestic fowl contribute to the preovulatory surge of progesterone which has been observed in the peripheral blood.

Oestrogen producing adrenocortical tumours are extremely rare. We report a 65-year-old woman who presented with abnormal vaginal bleeding, with no significant abnormalities in her uterus or ovaries, who was found to have a right adrenal mass by radiological examination. Excessive secretion of oestrogens from the tumour was demonstrated by adrenal venous sampling. Basal levels of corticosteroids were within normal limits. Adrenalectomy was performed and pathological examination revealed an adrenocortical adenoma measuring 5.5 cm in its greatest dimension, in which both clear and compact tumour cells were observed. Oestrogen levels normalized following the removal of the adrenal mass. Tissue concentrations of oestrone and oestradiol in the tumour were 6.9 (69.5 pmol/g wet tissue weight) and 34.6 (93.6 pmol/g wet tissue weight)-fold greater respectively than those of adjacent non-neoplastic adrenal cortex. Aromatase activity in the tumour tissue determined by the 3H-water method was 118.6 pmol/h/mg protein, equivalent to that of a full-term human placenta. Immunohistochemical analysis of aromatase demonstrated immunoreactivity in the tumour cells, especially in compact cells, but not in adjacent non-neoplastic adrenal cells. This is the first reported case of an oestrogen producing adrenocortical adenoma in which aromatase in the tumour cells was documented.

Synthesis of the biologically active oestrogen, oestradiol, within breast tumours makes an important contribution to the high concentrations of oestrogens which are present in malignant breast tissues. In breast tumours, oestrone is preferentially converted to oestradiol by the Type I oestradiol 17 beta-hydroxysteroid dehydrogenase (E2DH). Several growth factors, such as insulin-like growth factor Type I, and cytokines, such as Tumour Necrosis Factor alpha (TNF alpha), have been shown to stimulate E2DH activity in MCF-7 breast cancer cells. As little is known about the regulation of Type I E2DH expression and activity in other breast cancer cell lines, the expression and activity of this enzyme was examined in other oestrogen receptor positive and also oestrogen receptor negative breast cancer cell lines. As it is possible that E2DH activity may be limited by co-factor availability, the effects of exogenous co-factors on enzyme activity in these cell lines was also investigated. For T47D and BT20 breast cancer cells, the addition of exogenous co-factors was found to enhance enzyme activity. TNF alpha, in addition to stimulating E2DH activity in MCF-7 cells, also increased activity in T47D and MDA-MB-231 cells, although to a lesser extent than in MCF-7 cells. An investigation of signalling pathways involved in the regulation of E2DH activity revealed that stimulation of both the protein kinase C (PKC) and PKA pathways may be involved in regulation of E2DH activity. As several growth factors and cytokines have now been found to be involved in regulating E2DH activity, the role that macrophages and lymphocytes have in supplying these factors and the mechanism by which these factors may stimulate tumour growth, is also reviewed.

Transforming growth factor beta (TGF-beta) is a multifunctional regulator of cellular growth and differentiation in many cell types and has a growth inhibitory effect on mammary epithelial cells. The TGF-beta 2 isoform has been shown to be present in high concentrations in breast cyst fluid and might have a protective role in breast cancer. In addition, oestrogens play an important role in breast cancer development, and oestrone sulphate (E1S) might be the main source of active oestrogens in the breast. The aim of this study was to assess the effect of TGF-beta 2 on oestrogen synthesis in an attempt to understand the mechanism by which TGF-beta 2 may exert a protective effect in breast cancer. In this study, higher concentrations of TGF-beta 2 significantly inhibited the conversion of E1S to oestrone (E1) and the conversion of E1 to the potent oestrogen, oestradiol (E2). TGF-beta 2 did not have any effect on MCF-7 cell growth or on E2 to E1 conversion. In conclusion, TGF-beta 2 might exert a protective role in breast cancer by reducing the amount of active oestrogens present in the breast.