The effect of different regimens of oestrogens on the clotting and fibrinolytic system of the post-menopausal woman

The effects of six different regimens of hormone replacement therapy on coagulation, fibrinolysis and platelet aggregation were sudied in 33 symptomatic, post-menopausal women. Studies were performed before and after 3 months of therapy in the six treatment groups, Premarin, Progynova, Harmogen, Serial 28, ethynodiol diacetate and a testosterone and oestradiol implant. No changes in any parameter were detected following administration of Premarin, Progynova or an implant of testosterone and oestradiol. Serial 28 produced a significant increase in plasminogen concentration and increased the extent of platelet aggregation in 0.5 micron adrenalin solution. Harmogen produced an increase in the extent of platelet aggregation in 1.0 micron adrenalin solution, but a decrease in the rate of platelet aggregation in 1.0 micron solution. Ethynodiol diacetate caused a significant decrease in the kaolin-cephalin clotting time but decreased the extent of platelet aggregation in 0.5 and 1.0 micron solutions of adrenalin. FDPs developed following therapy in 9 of the 33 patients. These were evenly distributed between the groups. No patients had any change in anti-Xa concentration, platelet count or platelet aggregation in thrombin.

Effects of estrogen in the regulation of nitric oxide pathway during development of hypertension in rats

A down-regulation of nitric oxide (NO) synthesis has been involved in the genesis of cardiovascular complications associated with hypertension. This study was designed to assess the role of estrogen in the modulation of the pressor response elicited by N-methyl-L-arginine (L-NMA) in conscious spontaneously hypertensive (SHR) rats before and after ovariectomy. Four-week-old female SHR (n = 6) and age matched Wistar-Kyoto (WKY; control n = 7) rats were treated with mestranol (50 micrograms/100 g BW) twice a week for 8 weeks. At week 12, SHR and WKY were instrumented with catheters in the femoral artery and vein. L-NMA (30 mg/kg, i.v.) was infused over 1 min in SHR and WKY rats prior to and 3 weeks following ovariectomy. Results were compared to control rats, non-estrogen treated female SHR (n = 6) and WKY (n = 6). Our data show that the pressor response induced by L-NMA in estrogen-treated SHR was similar to estrogen-treated WKY (29 +/- 4 vs 25 +/- 2 mmHg). As compared to intact SHR and WKY, our data demonstrate that 3 weeks following ovariectomy, baseline blood pressure increased by 15% in SHR but remained unchanged in ovariectomized WKY. Furthermore, the magnitude of the L-NMA-induced pressor effect was significantly decreased in ovariectomized SHR and WKY. Our data support the concept that estrogen treatment does not play a significant role in the modulation of NO pathway in female SHR, whereas the presence of an intact ovaria modulates the NO pathway in female WKY.

FSH and ovarian response: spontaneous recovery of pituitary-ovarian activity during the pill-free period vs. exogenous recombinant FSH during high-dose combined oral contraceptives

OBJECTIVE

Compare spontaneous recovery of pituitary-ovarian activity during the pill-free period following the correct use of low-dose oral contraceptives and subsequent ovarian function during the administration of exogenous recombinant FSH (recFSH) after switching to continued Lyndiol (2.5 mg lynestrenol + 0.05 mg ethinyl-oestradiol) medication.

DESIGN

Prospective, randomized, group-comparative, single-centre study. Following the monitoring of the pill-free period (week 1) and subsequent treatment with Lyndiol (for a total of 5 weeks), all subjects were randomly allocated to one of four groups receiving daily FSH injections for 1 week [75, 150, 225 IU recFSH or 150 IU purified urinary FSH (uFSH)] during the fourth week of Lyndiol use.

PATIENTS

Thirty-six healthy volunteers aged 18-39 years, prestudy oral contraceptive use for at least 3 months, cycle length between 24 and 35 days.

MEASUREMENTS

Serum FSH, LH and oestradiol (E2) concentrations as well as transvaginal ultrasound assessment of the number and diameter of follicles > 2 mm were used to monitor pituitary ovarian function.

RESULTS

At the start of the pill-free period following the prestudy contraceptive medication, 67% of the women presented with LH and FSH levels < 1 IU/l and only one follicle > 10 mm was observed. Initial levels of LH and FSH correlated (P < 0.05) with the extent of pituitary-ovarian activity during the pill-free period. At the end of the pill-free period a follicle > 10 mm had emerged in one subject only. During the first 3 days of Lyndiol use, seven women (19%) eventually showed at least one follicle > 10 mm. During combined exogenous FSH and Lyndiol administration, LH levels remained completely suppressed (< or = 0.5 IU/l) in all women studied. FSH levels and number and size of follicles increased with increasing doses of exogenous FSH in a dose-dependent manner. E2 levels remained low in all groups (< 150 pmol/l). During the week following FSH administration, FSH levels and E2 levels decreased gradually while the number of follicles > 10 mm still increased.

CONCLUSIONS

We have confirmed that dominant follicles > 10 mm are present at the end of the pill-free period and during the first days after resumption of pill intake. Once follicles > 10 mm arose at the end of the pill-free period, continued use of Lyndiol did not reduce follicle diameters. One week of Lyndiol reduces pituitary-ovarian activity to levels observed after 3 weeks of low-dose pills. FSH administration during Lyndiol resulted in dose-dependent follicle growth despite extremely low LH levels. E2 secretion (56 +/- 51 pmol/l) occurred to a limited and variable extent along with extremely low serum LH concentrations. Recovery of pituitary-ovarian activity at the end of the pill-free period is comparable to FSH levels and follicle dynamics following 7 days of 75-150 IU/l recFSH.

Rhesus macaque model for ovarian cancer chemoprevention

PURPOSE

The objective of the study reported here was to explore whether a nonhuman primate model could be developed for chemoprevention of ovarian cancer.

METHODS

An initial feasibility trial was done with three monkeys to determine tolerance for these drugs and for acquisition of surgical ovarian biopsy specimens. In the study, 19 female adult Macacca mulatta (rhesus macaques) were given fenretinide (4HPR) oral contraceptive (OCP), the combination of 4HPR+OCP, or no medication for three months. Laparotomy was performed before and after drug administration, and ovarian biopsy specimens were obtained to evaluate the potential for this animal as a model for ovarian cancer chemoprevention, as well as evaluating fluorescence spectroscopy and other potential biomarkers for ovarian cancer prevention studies.

RESULTS

The monkeys tolerated the drugs, surgeries, and acquisition of multiple ovarian biopsy specimens with resultant minimal morbidity. On initial data analysis, fluorescence spectroscopy was the marker that appeared the most promising.

CONCLUSIONS

On the basis of results of this study, this model merits further investigation. The rhesus monkey is an excellent candidate for a nonhuman primate model for ovarian cancer chemoprevention.

Histological changes induced by tibolone and estrogen/glucocorticoid on aging skin

OBJECTIVE

The aim of this study was to investigate the oral effects of tibolone and mestranol plus paramethasone on the skin of postmenopausal women. A second purpose was to determine endometrial thickness with transvaginal ultrasound.

MATERIALS AND METHODS

This randomized study was carried out in 39 healthy postmenopausal women. Skin biopsies were obtained from the thigh area by a single punch, before and after treatment, and the sections were evaluated. Current characteristics of both groups were measured at follow-up.

RESULTS

No gross differences were observed in size, distribution or imaging of collagen, elastic or reticular fibers. Statistically significant changes were found in the papillar dermis thickness. There were no statistically significant differences in the sonographic measurements.

CONCLUSION

The estrogen/glucocorticoid combination provides a way to evaluate in parallel the cellular metabolism effects on the irreversible aging process. The current results encourage widening these observations of the possible advantage of this combination, in order to alleviate the cellular degenerative process.

Effect of the separate and combined administration of mestranol and phenobarbital on the development of altered hepatic foci expressing placental form of glutathione S-transferase in the rat

The stages in the carcinogenesis process include initiation, promotion and progression. Although many characteristics of tumor promotion and promoting agents have been reported, relatively few studies on the effects of combinations of promoting agents have been detailed. For study of the combined effects of phenobarbital (PB) and mestranol (MS) in multistage rat hepatocarcinogenesis, an initiation-promotion protocol was developed. Female rats were injected i.p. at 5 days of age with either diethylnitrosamine (DEN) (10 mg/kg) or the solvent tricaprilyn. At weaning, approximately 10 rats from both the DEN-initiated and the solvent control groups were provided basal diet alone, PB (10, 100 or 500 mg/kg diet), MS (0.02 or 0.2 mg/kg diet) or various combinations of both PB and MS in the basal diet. At 8 months of age, the rats were killed and the livers removed, sectioned and fixed in ice-cold acetone. Sections of 5 microgram thickness were stained for placental glutathione S-transferase (PGST) expression, and the volume fraction of liver occupied by altered hepatic foci was determined by stereology. In addition, incorporation of bromodeoxyuridine into nuclei of PGST-expressing (focal) and non-PGST-expressing (non-focal) hepatocytes was determined. Administration of the highest dose of PB resulted in a significant decrease in non-focal hepatocyte labeling index, with a 4-fold differential between the focal and non-focal hepatocyte labeling index. Administration of 0.2 mg/kg diet MS resulted in effective promotion. The non-focal labeling index was increased and the focal labeling index was further enhanced (3-fold) relative to the non-focal index by this dose of MS. Combination of the lower MS dose with PB resulted in at least an additive promoting effect; however, a lower volume fraction was noted for the combination of low MS dose plus the highest PB dose. Combination of the higher MS dose with PB resulted in an elevation of volume fraction only for the middle PB dose. These findings indicate that the potency of promotion by mixtures is modulated by the dose of each component as well as by pharmacodynamic and pharmacokinetic properties of each component of the mixture.

Inverted skin changes induced by estrogen and estrogen/glucocorticoid on aging dermis

To evaluate hormone replacement therapy effects at the peripheral level, the present trial explored the oral effects of mestranol (80 micrograms/day for 10 days) and mestranol plus paramethasone (80 micrograms + 6 mg/day for 10 days) on the skin of postmenopausal women. This double-blind study included 13 patients. Skin biopsies were obtained from the thigh area by a single punch, 5 mm in diameter, before and after treatment, and the sections, six per sample, were micrometrically evaluated. Various features of the epidermis and dermis layers were stained using the hematoxylin and eosin, Masson, Verhoeff's and Gomori techniques. Statistically significant changes were found in the papillar dermis thickness; mestranol reduced it and mestranol plus paramethasone increased it. The current results encourage widening these observations of the possible advantage of this estrogen/glucocorticoid combination, in order to alleviate the cellular degenerative process.

[Effect of mestranol on pharmacokinetics of phenazone in the rabbit]

There was studied the influence of mestranol on the pharmacokinetics parameters of phenazone. There was proved the decrease AUC abridgement the period of semi duration for elimination phase and increase total clearance. On the base of these experiments there was able to make a conclusion that estrogens influence on the phenazone's pharmacokinetic probably by induction of microsomal enzymes of liver.

Tamoxifen inhibits hepatoma cell growth through an estrogen receptor independent mechanism

BACKGROUND/AIMS

Tamoxifen has previously been shown to prolong the survival of patients with advanced stages of hepatocellular carcinoma and it has been suggested that it inhibits the growth of hepatoma cells through an estrogen receptor-dependent mechanism. We have studied the effects of the synthetic estrogen, mestranol, and the antiestrogen, tamoxifen, on the growth regulation of hepatoma cells in vitro.

METHODS

Cells were maintained under fully estrogenized conditions and were deprived of estrogen shortly before conducting experiments.

RESULTS

In the human hepatoma cell line Hep 3B, tamoxifen inhibited cell growth in a concentration and time-dependent manner with effective concentrations ranging from 0.1 microM to 10 microM. Mestranol inhibited cell growth at a concentration of 10 microM and had an additive effect with tamoxifen on growth inhibition. Expression of estrogen receptors in hepatoma cells was not detected by enzyme immunoassay, Northern blot analysis or reporter gene expression assay. Furthermore, the introduction of estrogen receptors into Hep 3B cells did not alter the effect of tamoxifen and mestranol on cell growth.

CONCLUSIONS

This study suggests that tamoxifen inhibits the growth of Hep 3B hepatoma cells through an estrogen receptor-independent mechanism.

The co-mitogenic effects of various estrogens for TGF-alpha-induced DNA synthesis in cultured female rat hepatocytes

The synthetic estrogens ethinyl estradiol (EE) and mestranol (M) are weak complete hepatic carcinogens and potent tumor promoters. In vivo, EE and M cause a rapid but transient increase in liver growth. However, studies in cultured female rat hepatocytes indicate that EE is not a strong complete hepatic mitogen but rather enhances epidermal growth factor (EGF)-induced DNA synthesis and is thus classified as a co-mitogen (Yager, J.D., Zurlo, J. and Ni, N. (1991) Proc. Soc. Exptl. Biol. Med., 198, 667-674). The endogenous estrogen 17 beta-estradiol (E2) also exhibits co-mitogenic activity, enhancing the fraction of hepatocytes undergoing DNA synthesis induced by both EGF and transforming growth factor alpha (TGF-alpha) (Ni, N. and Yager, J.D. (1994) Hepatology, 19, 183-192). The objectives of the study reported here were: (1) to determine whether the co-mitogenic effects of EE and E2 extend to other synthetic estrogens including mestranol and diethylstilbestrol, and to alpha-zearalanol, a natural product with estrogenic activity; (2) to compare the co-mitogenic effects of endogenous estrogens including E2, estrone, estriol and the catechol metabolites 2- and 4-hydroxy-estradiol; and (3) to determine whether the conditioned medium from E2-treated hepatocytes has co-mitogenic activity. Female rat hepatocytes in primary culture were exposed to the various estrogens +/- TGF-alpha and DNA synthesis was determined by measuring [3H]thymidine incorporation into extracted DNA. The results show that the co-mitogenic effects previously observed with EE and E2 also extend to all of these estrogens and to the E2 catechol metabolites. Although the co-mitogenic potency of these estrogens does not correlate with their reported affinities to the estrogen receptor, their estrogenicity appears necessary since the non-estrogenic metabolite 2-methoxy-estradiol lacks co-mitogenic activity. In addition, enhancement of TGF-alpha-induced DNA synthesis by conditioned medium from E2-treated cells supports the notion that a metabolite mediates its co-mitogenic effect.

Modulatory influence of oral contraceptives on mammary growth pattern of normal and ovariectomised mice

The present study reports the modulatory influence of oral contraceptive formulations, Ovral (0.05 mg ethinylestradiol plus 0.5 mg norgestrel per pill), Noracycline (0.05 mg ethinylestradiol plus 0.1 mg lynestrenol per pill), Pearl (0.03 mg ethinylestradiol plus 0.30 mg norgestrel) and Centchroman (30 mg), on the growth and developmental pattern of murine mammary epithelium in normal as well as ovariectomised mice. Oral treatments of ovariectomised mice for 15 days with doses D1 (1/5th of a pill) and D2 (1/10th of a pill) of Ovral, Noracycline and Pearl enhanced the diameter of the terminal end buds (TEBS) and lateral buds (LBS) significantly. The increase in the diameters of TEBS and LBS on treatment with similar doses of Centchroman were not much significant. Hence, it may be concluded from the present study that the growth and development pattern of mammary epithelium can be modulated by treatment with oral contraceptives Oral, Noracycline, Pearl and Centchroman which is indicated by the increase in the diameters of TEBS and LBS.

Long-term effect of low-dose combined steroid contraceptives on body iron status

The present study was aimed to evaluate iron metabolism in active and healthy adult women having taken oral contraceptives (OC) long-term. Mean dietary iron intake in age-matched control and experimental groups was adequate. Serum ferritin used as a marker for body iron stores was marginal in both groups underlying a high prevalence of deficient-iron reserves among subjects. This parameter was not correlated to the iron content of the diet. The serum iron concentration was significantly higher in OC users than control subjects (p less than 0.001). Biochemical results commanded a discussion on the pertinence of evaluating the total dietary iron intake and on the sensitivity of biochemical methods used to assess the iron status.

Effects of norethisterone on pressor response to angiotensin II in men

OBJECTIVE

We examined the effects of norethisterone and/or mestranol on the pressor response to angiotensin II in 20 healthy men.

METHODS

Four study protocols were used: I) mestranol 0.08 mg/day for 6 days followed by mestranol plus norethisterone 20 mg/day for 6 days, II) mestranol 0.16 mg/day for 6 days followed by norethisterone alone 10 mg/day for 6 days, III) mestranol 0.24 mg/day followed by norethisterone 20 mg/day for 6 days, and IV) norethisterone 20 mg/day for 6 days. The angiotensin II dose to elicit a 20-mmHg rise in diastolic blood pressure was considered the effective pressor dose. This was determined before each protocol, at the end of the mestranol-alone portion, and at the end of the norethisterone portion. Subjects in study III also underwent measurement of plasma prostanoid levels, plasma renin activity and concentration, and estradiol and progesterone just before each angiotensin II infusion. Subjects in studies I and III underwent measurement of mean platelet volume, complete blood counts, liver function tests, and coagulation factors before each angiotensin II infusion.

RESULTS

Whereas mestranol had no apparent effect on angiotensin II pressor response, norethisterone at a dose of 20 mg/day (with or without concurrent mestranol administration) caused a significant decrease in pressor responsiveness to angiotensin II. No changes in plasma prostanoids or renin could be found that would account for the change in pressor response.

CONCLUSION

These findings indicate that the refractoriness to angiotensin II induced by norethisterone was related to its progestogenic properties.

Estrogen protection against atherosclerosis and synthetic estrogen production of cirrhosis in the rabbit

Two artificial estrogens, ethinyl estradiol and mestranol, were found to cause cirrhosis in the rabbit liver during a study of atherosclerosis. These drugs showed protective effects against atherosclerosis in cholesterol-fed rabbits when administered orally (1 ppm in diet). These drugs and two naturally occurring estrogens, estrone and estradiol, were similarly effective when administered intramuscularly (1.5 mg per rabbit per week) to rabbits fed a diet lower in cholesterol. Reduction by estrogens of plasma cholesterol did not fully account for the reduction of extent of aortic atherosclerosis. Also, no differences in aortic or platelet eicosanoid production from exogenous arachidonic acid were found to explain the effect on atherogenesis. The 2 artificially modified estrogens, ethinyl estradiol and mestranol, caused portal fibrosis with biliary proliferation (even in rabbits not fed cholesterol). Estrone, estradiol, and testosterone were not injurious in this regard at the dosages used. Only the unmodified estrogens reduced atherosclerosis without damaging the rabbit liver.

Effects of oral contraceptive pills on drug metabolizing enzymes and acid soluble sulfhydryl level in mouse liver

The present paper reports the modulatory influence of two widely used combined oral contraceptive pills "OVRAL" and "NORACYCLINE" on hepatic phase I and II drug metabolizing enzymes and acid soluble sulfhydryl group of the mouse. Three different doses of the pills were used in this study i.e. D1 (1/2000th of a pill), D2 (1/200th of a pill) and D3 (1/20th of a pill). The sulfhydryl group increased significantly with the D1 and D2 dose of Ovral and the D2 dose of Noracycline. Dose D2 of both pills decreased cyt.P450 and cyt.b5 contents. D3 of Noracycline, however increased both the cytochrome levels. Dose D3 of Ovral and all three doses of Noracycline reduced the glutathione S-transferase activity.

Effect of long-term triphasic oral contraceptive use on glucose tolerance and insulin secretion

This study was designed to compare the effects of two low-dose triphasic oral contraceptives (OCs) on glucose tolerance and insulin secretion. Fifty-seven women were randomized to receive OCs containing ethinyl estradiol and either levonorgestrel or norethindrone. Ten subjects using nonhormonal contraception served as controls. Glucose tolerance and insulin secretion were measured at baseline and at 6 and 12 months after an oral glucose stimulus. Both preparations produced a relative hyperglycemia at 6 and 12 months compared with baseline, but within the norms for glucose tolerance. The insulin response, measured in 48 treated and eight control subjects, also increased over 12 months in both treated groups, but the total insulin area was within the range of the reference laboratory. Such minor changes have not been associated with cardiovascular diseases and support the safety of low-dose triphasic preparations.

Effect of estrogen/progestin administration on the ovarian response to gonadotropins: a randomized, prospective study

The findings of our study indicate that women pretreated with E/progestin demonstrate increased gonadotropin requirements when undergoing ovulation induction. Whether this treatment has a significant effect on the outcome of ovulation induction in patients receiving gonadotropins remains to be established.

Gene expression of macrophage colony-stimulating factor and its receptor in human placenta and decidua

Macrophage colony-stimulating factor (M-CSF) induces proliferation of monocyte/macrophage progenitor cells and can also activate some functions of mature cells including fetally derived placental cells. To study the role of M-CSF in the pregnant female reproductive tract, the expression of M-CSF mRNA and its receptor, c-fms proto-oncogene, in human placenta and decidua was identified. M-CSF and c-fms mRNAs, 4.7Kb and 3.9Kb respectively, were detected by Northern blotting in the early stage placenta and subsequently increased during pregnancy. These mRNAs were not detected in the nonpregnant endometrium but were strongly induced in maternal decidua with the same mRNA size as in the placenta. Northern blot hybridization on the endometrium of a pseudopregnant uterus revealed that the expression of endometrial M-CSF and c-fms mRNAs is regulated by synergistic action of female sex steroid hormones. These findings indicate that, in an autocrine and/or paracrine manner, M-CSF is deeply involved in the local proliferation and differentiation of cells at the materno-fetal interface, and support the placental immunotrophism hypothesis.

Prostaglandins: PGF2 alpha, PGE2, 6-keto-PGF1 alpha and TXB2 serum levels in dysmenorrheic adolescents before, during and after treatment with oral contraceptives

Ten adolescents with primary dysmenorrhea (PD) were treated with the oral contraceptive (OC) Lyndiol 2.5 mg (R) for one cycle. The levels of PGF2 alpha, PGE2 and the metabolites of PGI2 and TXA2: 6-keto-PGF1 alpha and TXB2 were tested by a radioimmunoassay method during the 1st and 23rd day of the pre-treatment cycle (PrTC), the 23rd day of treatment (TC) and the 1st day of the post-treatment cycle (PoTC). The ratios PGF2 alpha/PGE2 and TXB2/6-keto-PGF1 alpha were also tested and compared during the above-mentioned days. Analytical comparison was made, for each Prostaglandin (PG) separately, between the 1st day of the PrTC and PoTC as well as the 23rd day of the PrTC and TC, respectively. All PG levels during TC and PoTC were found significantly lower, compared to those of the PrTC respectively. With regard to the ratios mentioned above, no statistically significant differences were found on the same days and cycles as previously stated. The reduction of the PG levels in PD patients after treatment with oral contraceptives, together with an improvement of the clinical findings of the disease, support the theory that oral contraceptives can be used for the treatment of PD cases, especially for those adolescents who also desire a contraceptive method.

Effect of oral contraceptives on adrenocorticotropin and growth hormone secretion following CRH and GHRH administration

Previous investigations have demonstrated that basal ACTH plasma levels are reduced and that GH levels are either increased or unchanged in women taking oral contraceptives. The purpose of the present investigation was to determine the secretion of ACTH and GH following an intravenous infusion of human corticotropin releasing hormone (CRH) and human growth hormone releasing hormone (GHRH) in control women (N = 8) and in women taking a triphasic oral contraceptive (N = 9). The studies were initiated between 7:00 and 9:00 a.m. and all women were fasting. An intravenous catheter attached to a 3-way stopcock was used for blood sampling and to inject a bolus of CRH and GHRH (1 microgram/kg). Plasma samples were frozen immediately and stored at -70 degrees C until assayed for content of ACTH and GH by radioimmunoassay. The plasma levels of ACTH and GH increased following infusion of CRH and GHRH in all women. The mean plasma levels of growth hormone were not statistically different in oral contraceptive users compared to normal women. In contrast, ACTH plasma levels in oral contraceptive users were reduced approximately 25% overall, and significantly lower (p less than 0.04) at 120 minutes following the CRH infusion compared to controls. In conclusion, the GHRH-stimulated GH release was similar in normal women and oral contraceptive users. CRH-stimulated ACTH release was modestly reduced in oral contraceptive users compared to normal women suggesting that estrogens and progestogens may have a suppressive effect on the release of ACTH by the pituitary.

[Pharmacologic arrest of lactation. Comparison of Deprenon, lisuride, terguride and mestranol]

The authors compared the arrest of lactation by terguride, lisuride and deprenone. Terguride was administered to 14 women 2 X 0.5 mg by the oral route or 4 X 0.2 mg by the oral route for 21 days, lisuride to 41 women 2 X 0.5 mg or 4 X 0.2 mg by the oral route for 21 days, deprenone to 8 women 4 X 0.5 mg per day by the oral route for 21 days. Thus treated women were compared with women where lactation was arrested by mestranol, 0.15 mg per day for 7 days (15 women) and with normally lactating puerperial women (12 women). As expected, all tested methods were effective. No serious side-effects were observed. In the overall evaluation of different procedures where we included the suppression of lactation, the drop of the prolactin level, the incidence of the rebound phenomenon and side-effects of treatment, terguride and lisuride proved more suitable than deprenone and mestranol. The results of terguride were slightly more favourable than those of lisuride.

Hormone prevention of mammary carcinogenesis by norethynodrel-mestranol

The observation that the susceptibility of the mammary gland to chemical carcinogenesis is inversely related to its level of hormonally induced differentiation led us to test whether treatment of virgin rats with an estrogenic-progestagenic hormone combination protected the gland against this carcinogenesis. Virgin Sprague-Dawley rats aged 45, 55, 65, or 75 days had implanted subcutaneously for 21 days a pellet containing norethynodrel-mestranol (NM) (98.5%-1.5%) at two doses, a physiological or low dose (LD) of 0.5 mg, equivalent to the dose used in Enovid for contraception in humans, and a pharmacological or high dose (HD) of 5.0 mg. Twenty-one days after NM pellet removal, the mammary glands of 5 animals per group were examined for the number of terminal end buds (TEBs), terminal ducts (TDs), alveolar buds (ABs) and lobules, and the DNA labeling index (DNA-LI). The remaining animals received 8 mg 7,12-dimethylbenz(a) anthracene (DMBA)/100 g body weight, and tumorigenesis was evaluated at 24 weeks. The percentage of TEBs decreased with age, and further with NM treatment at both doses. Treatment did not significantly modify the percentage of TDs, but increased that of ABs in most groups. The DNA-LI of TEBs remained constant, even during aging and after treatment, whereas both aging and treatment reduced DNA-LI in TDs and ABs. Tumor incidence declined with increasing age from 75% to 44% in the 45 and 75 day-old control groups respectively. Adenocarcinoma incidence followed the same trend. NM treatment had a dose-related protective effect against development of tumors in general and of adenocarcinomas in particular. LD treatment resulted in a marginally significant reduction in adenocarcinoma incidence, whereas HD-treated animals were 0.24 times as likely as controls to develop carcinomas. There was a statistically significant correlation between the percentage of TEBs present in the gland at the time of carcinogen administration and the incidence of adenocarcinomas. It was concluded that treatment of virgin rats with the hormone combination norethynodrel-mestranol resulted in long lasting structural changes in the mammary gland which protected this organ from a subsequent carcinogenic insult.

The influence of mestranol and chlormadinone given separately or in combination on the effects evoked by a high-fat diet in female rabbits

The effect of mestranol and chlormadinone, the hormones contained in oral contraceptives: on lipid metabolism, some hemostatic parameters and on morphology of aorta, liver and heart was tested after separate or combined administration to mongrel female rabbits fed on a normal or high-fat diet (HFD). HFD administration led to typical atheromatous changes in the aortal intima. The hormones given together with HFD attenuated the augmentation of lipid serum level and the extent of atheromatous plaques in the intima. The percent content of alpha-lipoproteins was significantly lower in groups receiving HFD with or without the hormones than in the controls, but it was higher than in controls in the rabbits receiving the hormones alone. Chlormadinone given together with HFD potentiated atheromatous aortal changes, which occurred not only in the intima but also in the media. Mestranol given together with HFD significantly counteracted the development of atheromatous changes. Female rabbits receiving mestranol and chlormadinone displayed a significant increase in fibrinogen content, while those receiving mestranol showed an increased time of fibrinolysis. HFD produced a hepatic damage, which was augmented in rabbits concomitantly receiving the hormones. The hormones alone also displayed some, a less pronounced hepatotoxic action.

The influence of oral contraceptives on hormonal and metabolic homeostasis in young adolescents

In order to evaluate the effects of oral contraceptives on metabolic and endocrine function in teenagers, Norinyl 1/50 was begun in 46 12-17-year-old girls after a 16-hour-fasting blood sample was obtained for glucose, insulin, glucagon, growth hormone, luteinizing hormone, follicle-stimulating hormone, thyroid-stimulating hormone, prolactin, gluconeogenic substrates, total lipids, and cholesterol. Sampling was repeated at 6 and 12 months of therapy. Of the 46 patients enrolled in the study, 23 returned for follow-up after 6 months, and 13 completed the study. Blood sampling after 6 and 12 months of therapy demonstrated no significant changes (p greater than 0.05). Our results suggest that there were no changes in the metabolic or endocrine functions studied at 6 and 12 months on a medium-dose contraceptive agent.

Ovarian response to human menopausal gonadotropin following suppression with oral contraceptives

The main conclusion of this study is that a profound suppression of the pituitary and ovary can be associated with an inadequate response which may require a longer or different regimen of stimulation to achieve the desired outcome for IVF. We suggest that a pretreatment determination of E2 and gonadotropins can be of value to predict the nature of ovarian response in women with suppressed pituitary-ovarian function.

The biological expression of natural progesterone

Progesterone tablets were orally administered to women with no recent luteal activity. Three hypoestrogenic subjects who received, respectively, a single dose of 150 mg, 300 mg and 300 mg/d/7d, showed absorption and a progressive increase in circulating values in a dose-dependent manner. Five out of nine oligomenorrheic patients experienced withdrawal uterine bleeding with 150 mg/12/5d. Postmenopausal endometrium estrogenised by mestranol (n = 5) showed secretory histological changes after 300 mg/d/7d of oral progesterone. Six women with luteal insufficiency received 300 mg/d after control studies, and this dosage was effective in supplementing the circulating natural hormone so that it reached the level of that of fertile women. However, the endometrial progesterone uptake of these women showed no parallel increase. This study supports the clinical usage of oral progesterone and suggests evaluation of the dynamics of hormone uptake by the reproductive tissues.

The effects of estradiol and mestranol on alpha-adrenoceptors in select regions of the rat brain

The role of estrogens in modulating the concentration of CNS alpha-adrenoceptors has not been elucidated nor has it been determined how different estrogenic compounds affect these receptors. In this study brain alpha-1 and alpha-2-adrenoceptor binding was measured in female rats treated with estradiol and/or the synthetic estrogen mestranol. Rats treated biweekly for 12 weeks with mestranol (50 micrograms/100 g b.wt.) had a significant reduction in the apparent number of alpha-2-adrenoceptors in the frontal cortex and nucleus tractus solitarius (NTS), while apparent numbers of both alpha-1 and alpha-2-adrenoceptors were depressed in the locus coeruleus. Estradiol treatment (50 micrograms/100 g b.wt.) caused a significant elevation in apparent alpha-1-adrenoceptor numbers in the NTS relative to control. Alpha-adrenoceptor numbers in the rostral and caudal hypothalamus were not affected by either steroid treatment. These results suggest that regulation of apparent numbers of alpha-1 and alpha-2-adrenoceptors in the CNS depends on the type of estrogen used for treatment.

[Biological activity of C-ring-oxidized estrogens. The effect of 9 alpha-hydroxy-11 beta-nitroxy estrone and its acetate on the reproductive tract of male and female rats]

A study of the effects of 9 alpha-hydroxy-11 beta-nitroxy analogs of estrone and its acetate has shown that the insertion of 9,11-hydroxynitrate grouping in the estrogen molecule increased considerably antigonadotropic activity, determined by the inhibiting testicular growth effect, and the duration of uterotropic action in administration per os as compared to similar indices in subcutaneous injections. Dissociation of antigonadotropic and uterotropic activity was also noted in injection of the analogs in the stomach as a result of an increasing antigonadotropic effect. Experiments were performed on immature male and female rats.

Assessment of a new low-dose once-a-month injectable contraceptive

Norethisterone (NET) in combination with mestranol (ME), in a macrocrystalline aqueous suspension that provides sustained release of steroids, was assessed as a once-a-month injectable contraceptive in ten healthy women of reproductive age. The ovarian function was studied before and after the intramuscular administration of 12mg NET plus 1.2mg ME, delivered as crystals of 150 micron average size. Serial blood samples were taken throughout the injection intervals in all women to measure serum progesterone (P), estradiol (E2), and NET. The NET/ME preparation effectively inhibited ovulation in 23 out of the 25 injection intervals studied. The administration of this formulation induced in some women a small degree of follicular maturation not followed by luteal activity. The endometrial bleeding patterns after each injection showed a bleeding-free period of two to three weeks. The overall data demonstrate that the parenteral administration of a macrocrystalline steroid preparation of NET/ME can bring about a sustained release contraceptive system at a substantially lower dose than those currently employed in once-a-month injectable contraception.

Endothelium-dependent relaxation in estrogen-treated spontaneously hypertensive rats

Female spontaneously hypertensive rats (SHR) were injected subcutaneously with mestranol twice a week for 12 weeks. Isolated segments of thoracic aorta were then used to generate relaxation response curves to acetylcholine or ATP after precontraction with phenylephrine. Estrogen treatment attenuated the development of hypertension. Further, augmented endothelium-dependent relaxation to acetylcholine was seen in the estrogen-treated SHR. There was no difference, however, in the relaxation produced by ATP. Since the relaxation of both acetylcholine and ATP is endothelium-dependent, these findings suggest that different mechanisms may be involved in the relaxation produced by acetylcholine and ATP.

Effects of serum from oral contraceptive users on the metabolism of low density lipoprotein

The metabolism of radiolabeled 125I-low density lipoprotein (LDL) was studied in cultured human aortic smooth muscle cells (SMC) to investigate potential mechanisms contributing to heart attack and stroke in young women taking oral contraceptive (OC) preparations. No consistent difference was discerned in the capacity of these cells to bind and internalize LDL following 24-hour exposure to pooled lipoprotein-poor (d greater than 1.25 gm/ml) serum from nonsmoking OC users and controls. However, significantly (p greater than 0.01) less soluble radioactive material was released into the media from dishes containing SMC incubated with OC serum, indicating that their capacity to degrade LDL was impaired. Increased amounts of both cholesterol and cholesterol ester and electron microscopic evidence of lipid accumulation were found in SMC grown for 12 days under standard culture conditions with 10% OC serum. This combination of in vitro findings suggests that OC use may accelerate the development of cardiovascular disease in some women by modifying the metabolism of LDL by cells of the arterial wall.

Coagulation effects of oral contraception

In Europe and North America, estrogen/progestogen oral contraception has been associated with an increase in venous thromboembolism, myocardial infarction, and stroke. These hazards are found mainly in smokers and in women over the age of 35. Venous thromboembolism appears to correlate with the estrogen dosage, and the arterial complications with both the estrogen and progestogen components. Blood coagulation and vascular thrombosis are intimately related. Estrogen/progestogen oral contraception affects blood clotting by increasing plasma fibrinogen and the activity of coagulation factors, especially factors VII and X; antithrombin III, the inhibitor of coagulation, is usually decreased. Platelet activity is also enhanced with acceleration of aggregation. These changes create a state of hypercoagulability that, to a large extent, appears to be counterbalanced by increased fibrinolytic activity. Studies of the oral contraceptives in current use show that the coagulation effects depend on the dosage of estrogen and the type of progestogen used in combination. Current research is aimed at finding the estrogen/progestogen formulations that induce the least changes in the coagulation system and other physiologic processes. In this respect, the new low-dose formulations are a major step forward and should reduce the risk of vascular thrombotic complications.

The effects of contraceptive hormones on the replication of Chlamydia trachomatis in human endometrial cells

Several recent reports have documented a lower incidence of pelvic inflammatory disease (PID) among oral contraceptive users. The interpretation of this observation is difficult because the action of the contraceptive hormones may be directly by action on a specific host cell-parasite relationship, or indirectly via their action on other systems. In the present study we investigated the susceptibility of cultured human epithelial cells of the endometrium to infection by chlamydia and the influence of contraceptive steroids (ethinyl estradiol, mestranol and medroxyprogesterone acetate) upon replication of chlamydia in these cells. Forty-eight hours post-infection, elementary and reticulate bodies were observed in vacuoles of the infected endometrial cells by electron microscopy. Treatment of chlamydial-infected cells with contraceptive steroids in three different concentrations (10(-5)M, 10(-6)M and 10(-7)M) resulted in no effect on chlamydial replication, as examined by one-step growth curve. These results indicate that contraceptive hormones do not prevent chlamydial infection by direct effect on the replication of the agent.

Modulation of D-3-hydroxybutyrate dehydrogenase activity by estrogens

Liver D-3-hydroxybutyrate dehydrogenase (OHBD) is subjected to estrogen modulation. Estrogen action was demonstrated by (a) the lesser activity of liver OHBD in female rats, as compared with their male counterparts; (b) the increase of OHBD activity after ovariectomy of sexually mature rats; (c) the decrease of OHBD activity after treatment of gonadectomized or normal rats with 17 beta-estradiol or with artificial estrogens; (d) the decrease of OHBD activity in female rats during sexual development; (e) the effects of tamoxifen on the enzyme activity. The kinetics of OHBD reaction using liver mitochondria from estrogen-treated rats showed a 50% decrease of Vmax, as compared with the control value, in contrast to the other parameters which did not vary. These results, taken together with the effect of estrogens on liver mitochondrial phospholipids, point to a decreased content of OHBD in liver mitochondria from estrogen-treated rats. In contrast to OHBD, succinate dehydrogenase and cytochrome oxidase activities, mitochondrial protein synthesis and L-malate + L-glutamate oxidation by coupled liver mitochondria either increased or were not affected by estrogens. Kidney and heart OHBD were affected by ovariectomy and estrogens like the liver enzyme, though to a lesser degree.

Effect of mestranol on cell proliferation and angiotensinogen production in HepG2 cells: relation with the cell cycle and action of tamoxifen

The effects of the estrogen analog mestranol and of the antiestrogen tamoxifen on cell growth and the rate of angiotensinogen production were investigated in HepG2 cells, an hepato-carcinoma cell line of human origin. After 36 h of cell contact with high concentration of mestranol, a (10(-5) M) dose increased by 2-fold the rate of proliferation of HepG2 while reducing angiotensinogen production to below control level. Mestranol at 10(-6) M preferentially stimulated angiotensinogen production 5-fold, whereas cell growth rate was slightly increased. Comparable results were obtained for thymidine uptake in the course of the cell cycle, with a maximum increase for 10(-5) M mestranol, and an increase of angiotensinogen production for 10(-6) M mestranol. At 10(-6) M, tamoxifen acted as a pure antagonist by strongly inhibiting the stimulatory effect of mestranol and reducing angiotensinogen production to below the control level within 60 h. Tamoxifen did not affect the growth rate of HepG2 cells, either when administered alone or together with an equimolar concentration of mestranol.

Development of a low-dose monthly injectable contraceptive system: II. Pharmacokinetic and pharmacodynamic studies

A drug delivery system which provides a sustained release of norethindrone (NET) and mestranol (ME) for one month after a single intramuscular injection was assessed as a long-acting injectable contraceptive. The system is based upon well defined particle size crystals of the synthetic steroids maintained in suspension with saline solution. Eight healthy ovulating women volunteered for the study; they received a combination of 10 mg of NET plus 1 mg of ME in 1 ml of vehicle by intramuscular injection on day five of their menstrual cycle. Blood samples were drawn at 0, 1, 5, 10, 13, 17 and 21 days after drug administration. The immunoreactive serum levels of estradiol, progesterone, NET and ethinylestradiol were measured by specific radioimmunoassay procedures to assess ovarian function and the kinetic parameters of the synthetic steroids. This newly developed contraceptive system proved to be both effective, and long-lasting as well as devoid of side effects.

[Effects of oral contraceptives on fibrinolytic system among Japanese and American women]

Neither urinary plasmin-activity nor whole plasmin changed during the menstrual period of healthy women. Among Japanese women, pill-takers' recorded a markedly higher level of plasmin-activity than non-takers. No such trend was observed with whole plasmin and FDP. Among American women, no significant difference between non-users and users concerning the levels of whole plasmin, plasmin activity and FDP was observed. Among Japanese women, a significantly high level of plasmin activity was observed after administering pills for one year. Five out of six rabbits treated with thrombin intramuscularly showed a level of urinary plasmin activity which is five times higher than the control. The number of platelets decreased in two rabbits, the amounts of fibrinogen in one, and prothrombin time in one. Plasmin activity did not change in rabbits treated with 1/20 X and 1 X maximal tolerated dose (MTD) of norethisterone and mestranol, but was significantly increased by 50 X MTD of norethisterone and mestranol. On the other hand, when treated with both norethisterone and mestranol, plasmin activity did not change with 1/20 X but significantly increased with 1 X and 50 X. The activity of plasminogen activator in glomeruli of rats was increased dose-dependently by thrombin. However, norethisterone, mestranol, and norethisterone-mestranol failed to activate production of plasminogen activator. In conclusion, looking at the comparison of the fibrinolytic system of American and Japanese women, the fibrinolytic system in endothelial cells was found to react well to thrombin among Japanese but weakly among Americans. The weak reaction of the fibrinolytic system among Americans is suggested to be a cause of the increase in thrombosis.

Hormonal influence on experimental infections by a toxic shock strain of Staphylococcus aureus

Subcutaneous infection chambers in rabbits were infected with a strain of Staphylococcus aureus isolated from a patient with toxic shock syndrome. Estrogens (mestranol and 17-beta-estradiol) protected male rabbits and prolonged survival. Neither androgens (testosterone and dihydrotestosterone) nor progesterone affected the susceptibility of intact or ovarihysterectomized female rabbits.

Antimutagenic effects of natural and synthetic hormonal steroids

Among the steroid molecules, bile acids have been shown to have either a co- or an antimutagenic activity toward various direct and indirect acting mutagens in the Ames test. The present report extends such observations to other steroids having hormonal activity. The main effect of the active hormones is an inhibition of the genotoxicity of both direct and indirect acting mutagens. This effect is strictly structure-related. Moreover, both ethinyl oestradiol and mestranol, which are synthetic derivatives of beta-oestradiol largely used in contraceptive pills, are strong inhibitors of the mutagenicity, acting at nanomolar concentrations. The present article emphasizes the possible role of compounds with steroid structure as modulators of genotoxicity.

Effect of estrogens on the dexamethasone suppression test in nondepressed women

It is often suggested that estrogens may cause false-positive dexamethasone suppression test (DST) results. In this study of nine healthy, non-depressed women, DSTs were performed at baseline, immediately following administration of 21 days of oral contraceptives containing either 50 or 80 micrograms of mestranol (a synthetic estrogen) in combination with 1 mg of norethindrone (a synthetic progesterone), and 1 month after discontinuing the oral contraceptives. All subjects had post-dexamethasone cortisol levels less than or equal to 5 micrograms/dl during the study with the exception of two subjects in the mestranol 80 microgram group who had positive DSTs immediately following oral contraceptive administration; one of these subjects continued to have a positive DST 1 month later. DST results should be interpreted with caution if high dose estrogens are taken concurrently or have been recently discontinued.

In vitro effect of estrogens on the peroxidase activity of human endometrium

The effect of estrogen on the induction of human endometrial peroxidase was studied in vitro. When 17 beta-estradiol was added to the incubation medium, endometrial peroxidase activity was markedly increased, and the highest enzymatic activities were reached at about 12 h of incubation. The ability of estrogen and related compounds to increase peroxidase activity at a concentration of 10(-7) M was 17 beta-estradiol greater than estrone greater than 17 alpha-ethynylestradiol greater than estriol = diethylstilbestrol. Mestranol, progesterone, and testosterone had almost no activity. The induction of peroxidase by 17 beta-estradiol was inhibited by actinomycin D or cycloheximide. This method may be useful for determining the direct estrogenic effect of compounds in human endometrium.

The measurement of arterial smooth muscle cell mitogens in the blood of oral contraceptive users

We have previously shown that serum from young women receiving the same combined mestranol-norethindrone containing oral contraceptive (OC) preparation accelerated the proliferation of arterial smooth muscle cells (SMC) in tissue culture, and this in vitro effect was not a direct action of either of its estrogenic or progestogenic constituents. To identify the substance(s) which might contribute to this potentially atherogenic action, blood was obtained from 20 OC users and control women for the measurement of growth hormone, insulin, somatomedins (insulin-like growth factor IGF-I and IGF-II), and the platelet alpha-granule constituents platelet-derived growth factor (PDGF), beta-thromboglobulin, and platelet factor 4 (PF4). No difference was demonstrable between OC users and controls in the levels of any of these growth-promoting hormones, nor in plasma concentrations of any of the platelet alpha-granule proteins. These studies indicate that the enhanced mitogenicity found in OC sera is probably not attributable directly to these hormones or PDGF, and may instead result from an in vivo OC-induced alteration in other as yet unidentified mediators of cellular growth.