Exogenous estrogens and breast cancer in women with natural menopause.

Age, age at menopause, and calendar year at menopause were controlled as factors related to estrogen use. Data on 90 breast cancer patients and 83 conrols--all of whom had a natural menopause--showed no relationship between breast cancer and estrogen usage after the start of menopause symptoms.

PIP: 90 breast cancer patients aged 50-64 were compared with 83 controls matched for age, race, and socioeconomic class to determine the relationship between administration of exogenous estrogens and breast cancer when the factors of age, age at menopause, and calendar year were controlled. No harmful effect of estrogen administration was demonstrat ed, but a previous finding by the authors of a beneficial effect was neg ated. It is suggested, however, that there are still too many confounding factors in a study of this type for a harmful association to be revealed, and it is recommended that a case-control study be carried out in a large prepaid medical care system.

Effects of the antifertility drug enovid in five strains of mice, with particular regard to carcinogenesis.

PIP: The antifertility drug, Enovid, was tested for possible carcinogenicity in female mice of 5 specially selected strains: BALB/c, C3H, C3HfB, A, and C57BI. Enovid was chosen for testing since it is one of the most widely used oral contraceptives. The 5 strains of mice provided maximum genetic variation in the test animals. The drug was fed at 3 dose levels: 5 mcg/gm, 10 mcg/gm and 20 mcg/gm of food. The lowest dose did not prevent reproduction. The 10 mcg dose prevented some females from reproducing. The 20 mcg dose prevented all females from reproducing. The strains of mice differed in their response to Enovid. Weight gain was reduced in all strains. Effect on life-span varied, partly because of the tumors. Cervical and vaginal lesions showed invasion of the epithelium into the stroma but was limited, with few exceptions to the BALB/c females. In the BALB/c strain these lesions occurred in controls as well, but showed more progression and a higher incidence with the highest dose of Enovid. None of these lesions appeared grossly as tumors and none had extended beyond the vaginal wall or metastasized. They were observed only on histologic sections. Neither ovarian nor mammary gland tumors were increased in any strain. In the C3H strain such tumors seemed to be inhibited. In the C3HfB strain there was some inhibition of hepatomas and in the BALB/c strain some inhibition of adrenocortical adenoma. Chromophobe adenomas of the hypophysis were significantly increased in old C57BI females treated with the highest dose of Enovid. Offspring of Enovid-treated females showed no abnormalities. Enovid increased the occurrence and may have advanced the progression of epithelial lesions of the cervix and vagina of old BALB/c females. A study of the lesions in untreated females of this strain might help the understanding of carcinoma in situ in women and possibly the appearance of adeno-carcinoma of the vagina of young women whose mothers had been treated with stilbestrol during the first trimester to maintain pregnancy. Other neoplasms in this strain were not increased by the Enovid therapy. In the C3H strain mammary tumors were reduced by the Enovid and those that did occur were found later than in controls. Results from experimental animals should be applied to humans with care. Such results are of greatest value in directing attention to certain areas for investigation.^ieng

On the epidemiology of oral contraceptives and disease.

PIP: Adverse and beneficial effects, especially with regard to mortality rates, of oral contraceptives (OC) are reviewed. In 1980 approximately 80 million women used OCs worldwide. OCs were first marketed in the United States in the 1960's, but by the 1980's low-dose combination pills with less estrogen and progesterone content became widespread along with the minipill, injectable preparations depo- medroxyprogesterone DMPA, and norethindrone containing capsules. Relative disease risk estimates are based on cohort studies and case- control studies. The Royal College of General Practitioners RCGP Oral Contraceptive Study of 1974 involved 46,000 women aged over 15 (50% were OC users, 50% were nonusers) the Oxford Family Planning Association Contraceptive Study of 1976 recruited 17,032 women aged 25-39, 56% of whom used OCs, and the Walnut Creek Contraceptive Drug Study of 1981 studied 16,638 women aged 18-54 of whom 28% were OC users and 33% were former users. A somewhat elevated mortality among ever-users of OCs in the order of 20% seems to be indicated by these studies mostly attributable to diseases of the circulatory system. Current OC use is also a risk factor in thrombotic stroke of the order of 4 or 5, but former use of OCs lowers the risk to 2. The effect of OC dose and formulation, duration of use, and predisposing factors on hemorrhagic and thrombotic stroke appears to be inconclusive with varying data from different studies. There is evidence for some increase in ischemic heart disease among current OC users, and also a 2-fold increase of myocardial infarction (MI) when smoking, serum cholesterol, and hypertension is taken into account, moreover higher estrogen dosage also contributes to a higher incidence of MI. There is also a 5-fold increase of venous thromboembolism among OC users induced by duration of use and estrogen potency, as OCs seem to promote atherogenesis, although the roles of progesterone and estrogen are conflicting. combination pills reduce the rate of endometrial cancer, provided protection against ovarian cancer, and do not seem to increase breast cancer incidence, although the relative risk of cervical cancer is elevated. Mortality risks with older OCs outweigh the benefits.^ieng

Adenyl cyclase in the human placenta.

PIP: This study demonstrated that the human placenta possesses an adenyl cyclase system responsive to catecholamines and sodium flouride (NaF). 2.5 gm human term placentas were homogenized, centrifuged, washed, resuspended, and used as the enzyme system when placed with various agents. Incubations and the determination of adenosine 3', 5' monophosphate (cyclic AMP) formed were performed. Samples stimulated by .0001 M catecholamines (L-epinephrine or L-norepinephrine) or .01 M NaF had higher levels of cyclic AMP than the controls (p. 005 for catecholamine-treated samples and p. 001 for NaF-treated samples). A concentration of .0001 M L-epinephrine or L-norepinephrine appeared to be a maximum effective dose and .0000001 M a minimum. L=epinephrine was 10 times as effective in the stimulation as L-norepinephrine. With .0001 M, 499 and 439 pmoles/10 minutes per 25 mg of tissue was formed, whereas in the control (no added hormones) 256 pmoles/10 minutes were formed. 3.2% ethanol activated the system by a small amount (p.02). Propranolol alone did not appear to have any effect; however, the effect of .0001 M L-epinephrine was reduced by 95% in the presence of .00001 M propranolol. Propranolol had no effect on NaF-stimulated activity.^ieng

Tryptophan metabolism in women using steroid hormones for ovulation control.

PIP: This is an extension of work recently reported by Rose regarding young women using a combination of progesterone and estrogen for ovulation control. The 10 subjects studied had an abnormal xanthurenic acid excretion after a loading dose of tryptophan. After treatment with 2.5 mg norethynodrel and .1 mg mestranol (Enovid-E) from Days 5 to 24 of the the cycle, 24-hour urine specimens were collected before and after administration of 2 gm of L-tryptophan. They were then given 25 mg of pyridoxine hydrochloride 4 times a day during the 48 hours required to repeat the tryptophan loading test. Controls were 18 healthy women not taking drugs. Metabolites of trytophan determined were indican, anthranilic acid glucuronide, 0-aminohippuric acid, kynurenic acid, acetylkynurenine, kynurenine, 3-hydroxykynurenine, xanthurenic acid, and N-methyl-2-pyridone-5-carboxamide. Urine specimines were analyzed for these and for 4-pyridoxic acid taking usual precautions to avoid dietary factors or drugs which might vitiate the results. At first the ingestion of the steroid had no significant effect on the basal excretion of urinary tryptophan metabolites. However, after the loading dose of tryptophan, the subjects taking Enovid E- excreted a mean level of 697 micro-moles of xanthurenic acid compared with a mean level of 29.8 micro-moles in controls. Some of the other metabolites were also excreted in increased quantities: 3-hydroxykynurenine, kynurenine, kynurenic acid, and acetylkynurenine. The others were excreted in normal quantities. When experimental subjects were given 100 mg/day of supplemental pyridoxine hydrochloride, tryptophan metabolism was essentially normal. These results should be considered in human metabolic studies of pyridoxine-requiring enzyme systems.^ieng

The effects of an oral contraceptive on plasma growth hormone and glucose tolerance in two strains of rats.

Effects of an oral contraceptive on plasma growth hormone and glucose tolerance were studied in two strains of rats, Sprague-Dawley, a normal strain, and BHE, a carbohydrate-sensitive strain. Ethynyl estradiol and norgestrel, combined in a dose representative of the clinical preparation of Ovral were given for 21 days. Plasma growth hormone was measured following sodium pentobarbital stimulation. In both strains fasting blood glucose levels were unchanged following oral contraceptive therapy, however, a strain difference in response to a glucose load was found. With contraceptive steroid treatment, Sprague-Dawley rats developed an impaired tolerance to glucose during the latter part of the glucose tolerance test. BHE control animals had an abnormal response to a glucose load which improved with oral contraceptive therapy. No significant correlation between growth hormone changes and changes in glucose tolerance during contraceptive steroid treatment were observed. Both strains of rats receiving oral contraceptives gained less weight than their controls, however, the difference was statistically significant only in the Sprague-Dawley strain.

PIP: The effects of Ovral (norgestrel plus ethinyl estradiol) on plasma growth hormone (GH) levels and glucose tolerance were investigated in Sprague-Dawley and a carbohydrate-sensitive strain (BHE) of rats. Sodium pentobarbitol was used to stimulate GH production. Fasting blood glucose levels were not altered by treatment with Ovral in either strain. However, under a glucose load, Sprague-Dawley rats developed an impaired tolerance during the latter part of the glucose tolerance test, while treatment with the oral contraceptive improved an impaired response to glucose load in BHE animals. A good correlation between changes in GH and glucose tolerance during treatment could not be established. Sprague-Dawley rats had a significant (p less than .01) decrease in the rate of body weight increase compared with controls.

The effect of kind of carbohydrate in the diet and use of oral contraceptives on metabolism of young women. I. Blood and urinary lactate, uric acid, and phosphorus.

Six oral contraceptive (OC) users and six control subjects consumed diets in which 43% of the calories came from either sucrose or starch for 4 weeks in a cross-over design. Kind of carbohydrate in the diet had no effect on blood lactate response to a sucrose load, but lactate response of OC users was greater than that of control subjects. Kind of carbohydrate in the diet did not affect urinary lactate excretion after a sucrose load; however, OC users excreted more lactate than did controls and there was a significant interaction between dietary carbohydrate and OC use. Serum uric acid levels were significantly higher when the sucrose diet was consumed, but levels were not affected by OC use. Serum phosphorus levels were not affected by kind of carbohydrate in the diet but were higher in control subjects than in OC users and there was a significant interaction between diet and OC use. There were no significant differences in urinary uric acid and phosphorus excretions after sucrose loads or in 24-hr urinary excretions of uric acid, phosphorus, or urea due to kind of carbohydrate in the diet or OC use.

PIP: 6 oral contraceptive (OC) users and 6 control subjects aged 19-25 consumed prepared diets in which 43% of the calories came from either sucrose or starch for 4 weeks in a crossover design. OCs taken were Ovral (1), Ortho-Novum 1/50 (2), Ortho-Novum sequential (1), Oracon sequential (1), and Norlestrin (1). The kind of carbohydrate in the diet had no effect on blood lactate response to a sucrose load, but lactate response of OC users was greater than that of control subjects. Kind of carbohydrate in the diet did not affect urinary lactate excretion after a sucrose load; however, OC users excreted more lactate than did controls and there was a significant interaction between dietary carbohydrate and OC use. Serum uric acid levels were significantly higher when the sucrose diet was consumed, but levels were not affected by OC use. Serum phosphorus levels were not affected by kind of carbohydrate in the diet but were higher in control subjects than in OC users and there was a significant interaction between diet and OC use. There were no significant differences in urinary uric acid and phosphorus excretions after sucrose loads or in 24-hour urinary excretions of uric acid, phosphorus, or urea due to kind of carbohydrate in the diet or OC use.

Effect of oral contraceptive agents on nutrients: II. Vitamins.

Clinical, biochemical and nutritional data were collected from a large population of women using oral contraceptive agents. Higher incidence of abnormal clinical signs related to malnutrition were observed in the lower (B) as compared to the higher (A) socioeconomic groups, and also in the nonsupplemented groups as compared to the supplemented groups in the B subjects. As a rule the intake of oral contraceptive agent subjects of vitamin A, C, B6 and folic acid did not differ from that of the controls As expected, subjects from the supplemented groups had higher intake of vitamin A, C, B6, thiamin, riboflavin and folic acid, and A groups had higher intake of vitamin C, B6, riboflavin and folic acid. Increased plasma vitamin A and decreased carotene levels were observed in oral contraceptive agent users. In general oral contraceptive agents had little or no effect on plasma ascorbic acid. Urinary excretion of both thiamin and riboflavin in subjects using oral contraceptive agents were lower in A groups. Erythrocyte folate and plasma pyridoxal phosphate was decreased in A groups due to oral contraceptive agents. Subjects who took supplements had higher levels of plasma vitamin A, ascorbic acid and folate. But urinary thiamin and riboflavin were higher only in group A subjects who took supplements.

PIP: 18-45 year old women were tested to determine if the use of oral contraceptive agents (OCAs) affects the metabolism of vitamins. 4 different hormonal conditions and 2 socioeconomic levels in 8 groups were considered. Some of each socioeconomic level had taken Norinyl (1 mg norethisterone and 50 mcg mestranol) for 3 months or more. Others had used Ovral (.5 mg norgestrel and 5 mcg ethinyl estradiol) for equal periods. There were some in each group who had resumed use of OCAs during lactation within 5 weeks after pregnancy. Vitamins and mineral supplements were given to groups in each socioeconomic classification. They had a higher intake of Vitamins-A, C, thiamin, riboflavin, and folic acid. Incidence of clinical sings of malnutrition, such as dry skin, easily pluckable hair, angular lesions of the mouth, dental caries, bleeding gums, glossitis, and scaling of the skin, were significantly more frequently observed in the lower socioeconomic groups, and especially in nonsupplemented groups of women taking OCAs than in others. OCA administration increased plasma Vitamin-A levels but no socioeconomic effect was found. Plasma carotene levels were decreased by OCA therapy, but less so in the higher socioeconomic subjects. Plasma ascorbate was not affected by OCA use. Urinary excretion of thiamin annd riboflavin was decreased in subjects using OCAs. Erythrocyte folate and plasma pyridoxal phosphate (PLP) were also decreased. Results show a definite lowering effect of OCAs on red cell folate in subjects in the upper socioeconomic levels. There may also be a depletion of body stores of folic acid. It has been suggested that women who become pregnant soon after discontinuing OCA therapy have a high chance of developing folic acid deficiency during pregnancy. The lower socioeconomic group may be marginally deficient in folic acid. Similar results were obtained with thiamin and riboflavin. Changes due to OCA use with respect to thiamin, riboflavin, folate, and PLP were seen mainly in subjects in the upper lower socioeconomic groups may have prevented detection of smaller similar alterations due to OCA use.

The actions of ethinyloestradiol on the pituitary-adrenal system of the rat.

PIP: A study assessing the effects of estrogen on the pituitary-adrenal axis in rats is reported. In a series of experiments, rats were subjected to single and multiple doses of ethinyl estradiol (EE) and injections of ACTH. Administration of single doses of EE to quiescent rats brought increased plasma and adrenal gland corticosterone concentrations and in vitro corticosteroid production. In animals stressed by ether vapor, the plasma and in vitro corticosterone values were 40% lower than in controls although adrenal corticosterone levels were higher. Treatment with 500 mcg/kg EE per day for 7 days resulted in loss of body weight and hypertrophied, hyperdemic adrenal and pituitary glands in rats sacrificed 1 day after treatment. Rats studied 9 days after treatment showed normal growth and a regression in adrenal size but not in pituitary size. Plasma corticosterone concentration was unchanged 1 day after the 7-day treatment, adrenal weight increased by 58%, and in vivo steroid production was reduced suggesting a distinct hypersecretion of ACTH. Plasma protein binding capacity for corticosterone was unchanged by the 7-day treatment. After 9 days of rest from the EE regimen, an ACTH injection restored in vitro corticosteroid production to normal levels and raised plasma and adrenal content levels in stressed rats which suggests that the adrenal gland regained its function more quickly than the pituitary. Injection with long-acting ACTH caused a 56% increase in adrenal weight and no change in pituitary weight. Adrenal activity was not changed by ACTH treatment suggesting that the adrenal gland was insensitive to an acute release of endogenous ACTH. Inhibition of the pituitary-adrenal response to stress is most likely caused by inhibition of cholesterol synthesis although lack of precursor corticoid secretion due to exhaustion must be considered as a cause. Inhibition of the stress response after extended ACTH treatment is suggested to be due to a decreased sensitivity of the adrenal cortex although a reduction of circulating cholesterol cannot be excluded as a cause.^ieng

Proceedings: Quantitation of a new serum alpha-macroglobulin in malignant disease, steroid treatment, pregnancy and normal subjects.

PIP: Alpha-macroglobulin was quantitated in patients with malignant disease, steroid treatment, pregnancy, and in normal subjects using the rocket technique of Laurell. Women treated with combined estrogen/progestogen and with mestranol and men treated with stilbesterol showed rises in alpha-macroglobulins. Those treated with norethynodrel did not, indicating that the estrogen is the responsible agent. The level increased during pregnancy and decreased sharply in the first 2 days postpartum. 30% of normal women and 10% of normal men had detectable quantities of the protein (up to 4 mg/100 ml) in their serum. 92% of patients with malignant disease had detectable levels of protein--6 mg/100 ml or higher.^ieng

Anterior pituitary sensitivity in immature female rats stimulated with gonadotrophin releasing hormone in vivo: effect of priming with oestrogen, pregnant mare serum gonadotrophin or brain lesion.

PIP: Anterior pituitary sensitivity, assessed in terms of increments in plasma luteinizing hormone (LH) and follicle stimulating hormone (FSH) concentrations to stimulation with 1 or 2 injections of gonadotrophin releasing hormone (GnRH) was investigated in 26-day-old immature female rats which had received 1 of the following priming treatments: 1) 10 mcg estradiol benzoate (EB) as a single injection on Day 23 or Day 25 or on both days, 2) 10 IU pregnant mare serum gonadotrophin (PMSG) on Day 24, 3) an electrochemical brain lesion placed in the mediobasal hypothalamus on Day 23, or 4) control animals received either vehicle alone or a sham lesion. Pituitary sensitivity assessed at 1000 hours on Day 26 after 1 or 2 injections of GnRH was enhanced to a similar degree in the 3 groups treated with EB in terms of LH (p .01). FSH increased somewhat after EB treatment. In contrast, 48 hours after the injection of PMSG pituitary sensitivity, in terms of both LH and FSH, dropped sharply (p .001). Sensitivity to 1 injection of GnRH was unchanged in lesioned rats. However, a 2nd GnRH injection administered after an hour interval induced a slightly larger LH response in control animals. In another study, rats treated with EB on Day 23 and with 1 mg progesterone at 1200 hours on Day 26, pituitary sensitivity increased at both 1400 and 1700 hours as compared with that in the Day 23 EB-treated group at 1000 hours. PMSG-treated rats maintained their state of decreased responsiveness at 1400 hours, but exhibited increased sensitivity at the time of the gonadotropin surge (1700 hours).^ieng

Sexual behaviour of neonatally castrated rats injected during infancy with oestrogen and dihydrotestosterone.

Male rats were castrated on the day of birth (day 1) and injected with either testosterone, dihydrotestosterone, a synthetic oestrogen (RU 2858 + dihydrotestosterone, or oil from days 1 to 5. The aromatizable androgen, testosterone, and RU 2858 suppressed both cyclic gonadotrophin secretion, indicated by the absence of corpora lutea from implanted ovarian grafts, and the behavioural response to oestradiol benzoate + progesterone injections in adulthood. The 5alpha-reduced androgen, dihydrotestosterone alone did not affect gonadotrophin secretion or female receptive behaviour, but like testosterone, it increased penis development in response to testosterone propionate, and this was positively correlated with copulatory efficiency, i.e. the ratio of intromission to mount frequencies. Nevertheless, ejaculation only occurred among animals that had received testosterone or RU 2858 + dihydrotestosterone. The results support the concept that during the preinatal period, neural conversion of androgens to oestrogens is important both for the suppression of female gonadotrophin secretion and behaviour patterns as well as for the organization of male behaviour patterns. The 5alpha-reduction of unsaturated C19-steriods to dihydrotestosterone in peripheral tissues is also required to complete the development of the male genital tract.

PIP: Experiments were carried out to compare the masculine sexual behavior of male rats castrated on the day of birth (Day 1) and injected with testosterone (an aromatizable androgen), dihydrotestosterone (a nonaromatizable androgen), or an estrogen. Litters of Sprague-Dawlet rats were castrated under cryoanesthesia on Day 1 and assigned to 1 of 5 treatment groups: Group 1 received 50 mcg testosterone, Group 2 received 50 mcg dihydrotestosterone, Group 3 received RU 2858, Group 4 received 50 mcg dihydrotestosterone plus 1 mcg RU 2858, and Group 5 was given .05 ml oil. During Week 5 an ovary from a prepubertal female rat was transplanted under the left kidney capsule of each rat. Each rat was given 20 mcg estradiol benzoate per kg followed by .5 mg progesterone. Sexual receptivity was assessed. The aromatizable androgen, testosterone, and RU 2858 suppressed both cyclic gonadotropin secretion and the behavioral response to estradiol benzoate plus progesterone injections. Gonadotropin secretion or female receptive behavior was unaffected by dihydrotestosterone, but it increased penis development in response to testosterone propionate which was positively correlated with copulatory efficiency. Ejaculation only occurred in those animals that had recived testosterone or RU 2858 plus dihydrotestosteorne. During the perinatal period natural conversion of androgens to estrogens is needed for the suppression of gonadotropin secretion and behavior and for the development of male behavior patterns.

Drug-induced hypertension: pathogenesis and management.

PIP: Estrogenic compounds are the most important group of drugs that can induce hypertension. Studies have shown an incidence of significant hypertension amounting to less than 1% after 1 year of taking oral contraceptives and about 2% after 5 years. The ratio of the incidence of hypertension among ''takers'' to that of ''nontakers'' has been assessed at 1.8 by 1 study and 2.6 by another. Small but significant increments in systolic and diastolic pressures can be discerned during the first 2 years of treatment. Cessation of treatment has resulted in pressures returing to pretreatment levels within 3 months. In those previously normal the highest readings during oral contraceptive use were only 155/90 mm of Hg. Severe hypertension is more likely to occur in the predisposed, and malignant hypertension has been reported. Previous hypertension, toxemia of pregnancy, obesity, and nephropathy are predisposing conditions. Although progestagens, used alone, do not cause clinical hypertension the incidence of hypertension associated with an estrogen-progestogen combination was directly related to the dose of progestagen used. Weight gain is often observed in oral contraceptive users and is occasionally accompanied by edema and hypertension. There is a marked increase in the circulating level of renin substrate (angiotensinogen) which is caused by the estrogen component of the pill. The increase in renin substrate is associated with increase in plasma levels of renin activity, angiotensin 2, and aldosterone, together with a fall in plasma renin concentration. The suppression of plasma renin concentration can persist for weeks after stopping the pill. The factors responsible for hypertension are probably intrinsic and may be either neural, vascular, or renal. Patients taking oral contraceptives should have blood pressure checks at 6-month intervals, and more frequently in high risk cases. In the management of those with only mild blood pressure elevation, such patients should change to a preparation with the lowest available estrogen dosage, 30 mcg of ethinyl estradiol, or reserve the method for use during crucial periods of family planning. With moderate hypertension the oral contraceptive should be suspended for 3-6 months. If the blood pressure falls, oral contraceptives should not be resumed but another method recommended. Continuing hypertension requires further study and possibly elective sterilization. Severe hypertension requires withdrawal of the pill, urgent investigation, and treatment. Other drugs may cause hypertension. Management of these patients is outlined. Structural formulae of progesterone, norethisterone acetate, medroxyprogesterone acetate, and norgestrel are shown.^ieng

Effects of ethynyl estradiol on incorporation of (1-14C) oleate into triglyceride and ketone bodies by the liver.

PIP: The effect of ethinyl estradiol (EE) on the incorporation of (1-carbon-14) oleate into triglyceride and ketone bodies by the rat liver was investigated. Treatment with EE resulted in significant increases in the incorporation of oleate into hepatic (p less than .05) and perfusate (p less than .005) triglycerides. However, the incorporation of oleate into ketone body perfusate was significantly (p less than .001) reduced, though liver incorporation was not markedly affected. Liver uptake of fatty acid was somewhat lower in treated rats. Possible mechanisms for the increased rate of secretion of triglycerides following treatment with EE are briefly discussed.^ieng

Developmental correlation of higher levels of estrogen binding by macromolecules in rat liver supernatant and of increases in plasma renin substrate levels after estrogen administration.

PIP: Developmental correlation of higher levels of estrogen binding by macromolecules in rat liver supernatant and of increases in plasma renin substrate levels after estrogen administration is reported. Gel filtration columns were used to separate bound from free radioactivity in studying binding of radioactive estradiol to tissue supernatants. The liver of the prepubescent female rat has less estrogen-specific binding macromolecules than the adult (p less than .01). This difference in quantity was maintained when binding activities were partially purified by precipitation with ammonium sulfate at 30% saturation. After administration in vivo of 100 mcg of ethinyl estradiol (sc), plasma renin substrate (PRS) levels increased 167% above control in the adult female rat (p less than .05). The corresponding increase was only 15% in the prepubescent rat. In contrast, renin substrate levels were significantly increased in both the prepubescent and adult by administration of 4 mg/kg of dexamethasone (p less than .05). The marked increase in the amount of estrogen binding and PRS responsiveness to estrogen administration with sexual maturation indicates that the estrogen-binding protein may be an estrogen receptor involved in modulating synthesis of at least 1 plasma protein.^ieng

Effects of neomycin on the biliary excretion and enterohepatic circulation of mestranol and 17beta-oestradiol.

PIP: The continued circulation of free steroids depends on their resorption from the gut following the hydrolysis of biliary conjugates. In this study, the bile duct of female Wistar albino rats was cannulated. Animals receiving labeled steroids or labeled bile intraductally also had the duodenum fitted with a cannula connected with a dosing syringe. In neomycin-treated rats, recirculation was impaired up to 50%. The deconjugation of mestranol and estradiol biliary conjugates was shown in vitro uponiincubation with rat caecal microorganisms, and the inhibition of such hydrolysis by neomycin was observed in vitro. Neomycin pretreatment reduced the biliary excretion of mestranol and estradiol after intraductal administration. It was thought that suppression of the gut microflora by neomycin was a major factor in the impairment of the intrahepatic circulation of mestranol and estradiol metabolites. This effect may be important regarding the half-life of estrogenic compounds of the contraceptive pill.^ieng

Effect of long-term therapy with an oral contraceptive on some aspects of hepatic lipid metabolism in vitro.

PIP: The effect of Enovid (7.5 mg/kg of food) for both short and long periods of therapy in female Blue Spruce Farm rats was studied. Hepatic release of triglyceride and of cholesterol was measured. Tests were made in vitro. Treatment periods were 4 days of 1 year. The short-term treated group ingested 315 mcg/kg body weight of Enovid daily; the long-term treated group ingested 375 mcg/kg of body weight of Enovid daily. These are about 3 times the daily dose for humans. Animal livers were removed and placed in a perfusion apparatus. The perfusion technique is described. The adrenal glands were also removed and the lipid extract, after being similarly treated in the perfusion apparatus, was tested for cholesterol. Body weights of animals were reduced significantly (p less than .05) by both short- and long-term treatment. The amounts of food consumed were reduced only in the short-term tests. In neither group was change in liver weight found. Bile production was reduced 50% in rats treated 4 days but in those treated 1 year with Enovid no effect was noted when compared with controls. However, in both control and test animals, production of bile after 1 year was reduced by 70-75% as compared with younger animals. Perfusion flow rate in rats treated with Enovid for 1 year was significantly faster (p less than .02) than through livers in the control group. Glucose release was reduced by both short- and long-term Enovid therapy. Reduced food intake may have caused this effect in the short-term therapy. In the group treated with Enovid for 1 year, release of cholesterol and triglycerides into the perfusate was reduced 72 and 38%, respectively. This effect was not observed in the 4-day treated animals. Enovid had no effect on the weights of livers or on the concentration of either triglycerides or cholesterol in hepatic tissue after either form of therapy. No elevation of serum triglyceride was found. A 30% decrease in serum cholesterol was found after 4 days of Enovid therapy. However, in those treated 1 year, and in controls, there was a 100% increase over that of younger animals. Enovid had no effect on the weights of adrenal glands. Total sterol content of adrenal glands from animals treated 1 year was decreased significantly (p less than .05) but not in animals treated only 4 days. Results obtained may be attributed to the metabolic effects of the individual components of Enovid. Further experiments are in progress to examine the effects of each component on hepatic triglyceride transport. Each Enovid tablet contained 5 mg norethynodrel and .075 mg of mestranol.^ieng

Effects of oestrogen and androgen on the sexual behaviour responses of the ovariectomized ewe.

PIP: The secretion of gonadal steroid hormones that stimulate sexual behavior differs between males and females in 2 respects: the hormones are chemically different, estrogen and progesterone on 1 hand and androgen on the other, and their pattern of release into the blood stream differs according to the sex of the animal. Those produced by the female are released during a limited period whereas testosterone exhibits little day-to-day variation. 12 ovariectomized Ile-de-France ewes were injected either with 50 mg of estradiol benzoate of 10 mg or testosterone propionate 48 hours after the last of 5 daily injections of 25 mg of progesterone. In both cases the experimental females exhibited normal female sexual behavior. In a 2nd experiment, the ewes were injected daily for 4 weeks either with 50 mg of estradiol benzoate or with 10 mg of testosterone propionate. In both cases male patterns of sexual behavior appeared, but more intensely with androgen than with estrogen, and simultaneously, the ewes became receptive. However, receptivity declined rapidly after a few days of estrogen treatment. This decline did not occur with androgen.^ieng

Influence of chlorpromazine on the positive and negative feed-back mechanism of oestrogens in man.

PIP: It was determined whether all the different neuroendocrine actions of estrogen are competitively antagonized by phenothiazines to test the putative analogy between the 2 types of molecular receptor. 12 men aged 22-25 years were tested on 3 days and then given 2 X 20 mg ethinylestradiol (EE) for 4 days with either 2 X 50 mg chlorpromazine (6 cases) or a placebo (6 cases). Neurohypophyseal activity and adenohypophyseal activity were tested. There was a lack of significant changes in pulse, blood pressure, body weight, and psychosexual factors. Blood alkaline phosphatases decreased in all 12 men after estrogen, and an inhibitory effect of estrogens alone was seen on blood FSH and on the 2 and 5 fraction of urinary 17-keto-steroids. The neurophysine basal level and the growth hormone peak response to hypoglycemia showed a stimulatory effect. There was no effect on FSH by chlorpromazine or on the inhibition of 17-keto-steroids due to estrogens. However, chlorpromazine lessened the neurophysine increase and abolished the facilitatory effect of estrogens on growth hormone responsibeness to hypoglycemia. In 60% of the cases TSH blood levels were undetectable and unvaried.^ieng

Reduced incidence of endometrial cancer among postmenopausal women treated with progestogens.

PIP: Because of adverse publicity regarding increased risk of endometrial cancer in women receiving estrogen therapy, a 2-year prospective study was conducted in 1976 to determine the incidence of endometrial cancer in postmenopausal women. A retrospective study for the year 1975 was also added. A postmenopausal survey card for each patient recorded the patient's visit and clinical data, as well as hormone therapies (estrogen, progestogen, androgen). Postmenopausal women never treated with hormones were also provided survey cards. A total of 2088 patient-years of estrogen use was recorded during the combined 3-year study period (1975-77). 8 of the estrogen users had a diagnosis of adenocarcinoma of the endometrium for an annual incidence rate of 3.8/1000 women. 2 endometrial cancers were detected in the estrogen-progestogen users for a cancer incidence rate of 0.5/1000 (3792 patient-years of observation); this finding suggests that progestogen provides better protection against endometrial cancer compared to estrogens. This difference between estrogen users and estrogen-progestogen users was statistically significant (p ? 0.01). 1 endometrial malignancy occurred among estrogen vaginal cream users, giving an incidence of 1.7/1000. The patient used Premarin vaginal cream (1 gm thrice weekly) for 7 months before the cancer was diagnosed. No endometrial cancer was diagnosed in both the progestogen and androgen groups. Overall, 14 endometrial cancers out of 8170 years of observation were diagnosed in this clinic; annual incidence rate for the study period was 1.7/1000. 199 women with endometrial hyperplasia (a precancerous lesion) were treated with progestogens for 3 to 6 months. The hyperplastic endometrium returned to normal in 96.5%. It was suggested that all postmenopausal women with intact uterus be given the Progestogen Challenge Test and that progestogens be given to the women each month as long as bleeding follows. This should prevent the development of endometrial cancer in most women.^ieng