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PubMed1982

Estrogens augment the stimulation of ovarian aromatase activity by follicle-stimulating hormone in cultured rat granulosa cells.

The effects of estrogens on ovarian aromatase activity were investigated in vitro using granulosa cells from immature hypophysectomized estrogen-primed rats. The cells were cultured for 3 days in an androgen-free medium in the presence of follicle-stimulating hormone (FSH), with or without the specified estrogen. After washing, the cells were reincubated for 5 h with 10(-7) M androstenedione, and the formation of estrogens was measured. Estrogen production by control and diethylstilbestrol-treated cells was negligible, while FSH stimulated aromatase activity. Furthermore, concomitant treatment with diethylstilbestrol led to dose-dependent increases in the FSH-induced aromatase activity with an ED50 value of 4 X 10(-9) M and an apparent Vmax value 12- to 16-fold higher than those induced by FSH alone. The direct stimulatory effect of estrogens was time-dependent and was not accounted for by increases in cell protein. Various native and synthetic estrogens also augmented the FSH induction of aromatases (native estrogens: estradiol-17 beta = estrone greater than estradiol-17 alpha greater than estriol; synthetic estrogens: hexestrol greater than moxestrol greater than ethinyl estradiol much greater than chlorotrianisene and mestranol). The effect of estradiol-17 beta was dose-dependent with an ED50 value of 9 X 10(-9) M, which is within the physiological levels of follicular estradiol-17 beta. Although treatment with androgens also enhanced the FSH-induced aromatases, treatment with a progestin (R5020) or a mineralocorticoid (aldosterone) was without effect. Thus, estrogens directly augment the stimulation of granulosa cell aromatase activity by FSH. Follicular estrogens may activate intraovarian autoregulatory positive feedback mechanisms to enhance their own production, resulting in selective follicle maturation and the preovulatory estrogen surge.

Aldosterone↗
PubMed1980

[Multicomponent system of estrogen-binding proteins of the liver. Isolation and comparative properties of 4-5S and other rat liver high molecular weight proteins, which specifically bind estradiol].

Forms I and II of the estrogen receptors of female rat liver were isolated by desalting of the cytosol fraction desalting with 40% saturated (NH4)2SO4 with a subsequent gel-filtration through Ultragel AcA 44. In the absence of 0,3 M NaCl form I produces heavy aggregates and is eluted from Sepharose 6B in excluse volume. The molecular weight of from II under the same conditions as measured during gel-filtration and gradient centrifugation is 80 000. In the presence of 0,3 M NaCl the molecular weights of forms I and II are 63 000 and 77 000, respectively. The pH optima for the estradiol-binding activity of forms I and II are 6,8--8,5 and 7,4--9,1, respectively. Form II is more stable to heating and storage at 4 degrees. The binding activity of both forms of the receptors is eliminated by p-chloromercurybenzoate. The equilibrium constant for form II association with estradiol exceeds that of form I 2,5-fold and is equal to 2,4 x 10(10) M-1. The presence of 0,3 M NaCl does not affect this parameter in both cases. The association of forms I and II with estradiol and dissociation of the complexes are of a two-step type. The k+1 values for forms I and II are identical, whereas the k-1 value for form I is about two times that for form II. In terms of their competitive activity the hormone compounds tested can be arranged in the following order: estradiol less than or greater than hexestrol much greater than estrone congruent to estriol congruent to 17-deoxyestradiol much greater than 5 alpha-dihydroxytestosterone congruent to testosterone. Progesterone and corticosterone do not reveal competitive properties. The functional similarity of forms I and II of estrogen receptors from rat liver suggests that these proteins are isoreceptors.

Animals↗
PubMed1981

New aspects in the development of cytotoxic-linked estrogens for the control of breast neoplasia.

The interest of cytotoxic-linked estrogens as therapeutical drugs for controlling the growth of breast cancers relies on their potential binding to estrogen receptors (ER) in these cancers. 14, 15-alpha and beta epoxide derivatives of estradiol-17 alpha and 17 beta were investigated for their ER binding affinity and their cytotoxic activities on the MCF-7 and Evsa-T cell lines. 14, 15 alpha and beta-epoxides of estradiol 17 alpha as well as the 14, 15 alpha epoxide of estradiol 17 beta bound to ER. No compound revealed any cytotoxicity on the cell lines. A 11 beta-aziridine derivative of estrone showed significant binding activity to ER. Concentrations of 10(-7) and 10(-8) M of this compound act stimulating on the growth of MCF-7 cell line. 10(-6) M is slightly inhibitory. There is no effect on Evsa-T cells. Binitrogen mustard derivatives of hexestrol and diethylstilbestrol displayed a very low binding activity whereas mononitrogen mustards of estrone showed a significant binding activity. At concentrations of 10(-6) M all mustard compounds inhibited the growth of MCF-7 cell line. The inhibitory influence of the mononitrogen mustards were higher than those of the binitrogen mustards. With regard to the Evsa-T cells only mononitrogen mustard displayed a growth inhibiting effect.

Breast Neoplasms↗
PubMedDate not supplied

[Effect of the synestrol analog sigetin on serum lipid levels of lipoprotein lipid composition in rabbits].

Analogue of hexestrol sigethine, deprived of the estrogenic effect, was shown to decrease the content of cholesterol in blood serum, liver tissue and aorta, as well as to reduce the fraction of very low density lipoproteins and content of cholesterol in this fraction of hyperlipidemic rabbits. Diethylstilbestrol lowered the content of cholesterol in blood serum of intact rabbits. Simultaneous administration of diethylstilbestrol and sigethine decreased the concentration of triglycerides in blood serum, increased the fraction of alpha-lipoproteins and of cholesterol in the serum.

Animals↗
PubMed1976

Pharmacological and endocrinological studies on anabolic agents.

When used in connection with animal production the term "anabolic agents" covers a wide range. Ther steroidal male and female sex hormones are included in this list, as are the nonsteroidal estrogens. For the clinician and for the endocrinologist, anabolics are only steroids chemically related to testosterone and 19-nortestosterone. Estrogens, though possessing anabolic properties, too, do not belong to this class. This paper will deal with anabolic agents in in the stricter sense of which mainly trenbolone acetate combined with hexestrol has been recommended for bull and heifer fattening. To consider possible consumer injury from ingestion of meat from anabolic agent treated animals, it is necessary to know the pharmacological properties of the agents, the doses producing certain effects or might produce, and the levels of residues in the meat. Trenbolone acetate will be compared with the following anabolic agents: methenolone acetate, methandrostenolone, nandrone, androstanazole, and 19-nortestosterone. The activity spectrum of trenbolone acetate is similar to that of 19-nortestosterone or those anabolics that are derived from 19-nortestosterone. The compound has about three times stronger androgenic effect than testosterone propionate. Its index of dissociation between anabolic/androgenic activity is 2--3. This index is 3--10 for the other anabolic agents. As regards the virilizing potency, trenbolone acetate is also on the top of the list. It seems that androgenicity and degree of virilization run paralle. The antigonadotropic activity (inhibition of ovulation and testicular growth) of trenbolone acetate exceeds that of testosterone propionate by the factor 3. The compound is not estrogenic and seemingly not or only weakly progestationally active. In principle, the androgenic activity (symptoms of virilization) as well as the antigonadotropic effect (disturbances of the menstrual cycle in women, inhibition of spermiogenesis in men) of trenbolone acetate might be noted. This risk, however, can be excluded by mere calculation. In rats, 0.1 mg/kg trenbolone acetate have an antigonadotropic effect. This corresponds to a daily dose of 5--7 mg in humans. By the same extrapolation, a daily human dose of 100 mg can be calculated for androgenic activity. Such factors of conversion are, of course, not precise because rats are much less sensitive to androgens and anabolics than humans. Thus, testosterone propionate is active only in daily doses of 10--20 mg. If in humans trenbolone acetate also has three times the activity of testosterone propionate, effects in man had to be counted with not less than a daily intake of 3--5 mg trenbolone acetate. The dose which is recommended for livestock fattening is 300 mg. IT can, therefore, be excluded almost with certainty that the meat would contain such large amounts of hormone residues.

Anabolic Agents↗
PubMed1976

The effectiveness of anabolic agents in increasing rate of growth in farm animals; report on experiments in cattle.

In many countries anabolic agents are successfully used to increase the rate of growth of cattle. In the past widespread use was made of cheap synthetic estrogens such as diethylstilbestrol and hexestrol. However, new legislation in certain countries has restricted the use of synthetic estrogens. This has resulted in an intensive search by industry for alternative agents. On the one hand natural steroid hormones like estradiol, testosterone and progesterone were studied, while on the other hand products like an active compound of the resorcyclic acid lactones and the synthetic anabolic steroid trenbolone acetate were developed. Administration of anabolic agents to cattle is done in three ways. (1) The agent may be fed orally by incorporation into the concentrate feed or as a simple additive top dressing. If the agent is metabolised in the rumen, oral administration may still be possible by using coated materials which avoid rumen metabolism with subsequent absorption of the steroid from the small intestine. (2) The agent may be administered as a slow release implant, e.g. trenbolone acetate or various combined preparations of an androgen and estrogen. (3) Administration by repeated injection. This latter method is often impractical. Anabolic agents are normally administered to beef cattle or culled dairy cows during the last few months of the finishing period. Maximum weight gain performance in different types of cattle requires selection of the correct anabolic agent. Increased performance in female cattle is better when an androgenic steroid is administered. However, in intact males (bulls) best performance is only obtained when an estrogen, alone or in combination with an androgen, is administered. Castrate animals (steers) do best if a smaller amount of estrogen is combined with an androgen and administered, however there is evidence that androgen alone is as effective. In summary therefore, an additional response in growth of cattle may require the presence of an estrogen, as endogenous estrogen in the female and the exogenous form in the male. Only when this condition is met will administration of androgenic anabolic steroids result in maximum benefit, often improving the effect of estrogen given on its own. Anabolic agents have some beneficial effect on appetite. They may not affect the digestive processes of the alimentary system. They have a positive effect on nitrogen retention. The liver almost certainly has a central role in the regulation of nitrogen retention. Recent experiments suggest that urea entry rates in ruminants may be lowered, thus making available more nitrogen for protein synthesis. Muscle protein synthesis is altered with changes in carcass conformation. There are some changes in fat redistribution. How all these processes are integrated is not yet known. The possibility that anabolic agents establish a new hormonal status which is favourable to growth will be discussed...

Anabolic Agents↗
PubMed1997

Geiparvarin and derivatives in combination with taxol: effect on microtubular organization in 3T3 fibroblasts.

Geiparvarin, a natural product that exhibits antiproliferative activity, inhibits the growth of various tumour cell lines with a mechanism of action so far unknown. Our preliminary findings showed that geiparvarin and some derivatives obtained from its conjugation with diethylstilboestrol and meso-hexestrol significantly inhibit taxol-induced in vitro polymerization of both tubulin and microtubular protein. In this study we investigated the effect of geiparvarin and of the oestrogen-combined derivatives on the cellular microtubular network of fibroblasts. Geiparvarin altered the microtubular organization of fibroblasts and strengthened the derangement of the microtubular pattern in cells exposed simultaneously to taxol. However, the microtubular network remained quite well organized in fibroblasts exposed to geiparvarin and preincubated with taxol, which in this case prevented the deranging effect of the former. The antimicrotubular activity of the oestrogen-combined derivatives was more similar to that of geiparvarin than to that of the oestrogens, and often this activity was stronger than that of each reference drug alone; the cytotoxic activity examined in the same experimental conditions generally confirmed the microscopic analysis.

3T3 Cells↗
PubMedDate not supplied

Experimental studies on the dynamics of the scaring effect of some ointments.

The ointment studied is made by us in the laboratory. He includes the following ingredients: a bee-keeping product soved in sunflower oil, an antioxidant, hexestrole, and a proper preserving medium. The idea was to create a product which is capable to accelerate the scarring process of the plague produced by burns. Thus, after 10-12 days we can observe a favourable clinical evolution. Anatomo-microscopy is obvious a gradually regenerating epithelium and the subjacent dermis remains slightly infiltrated. The final result is an aesthetic scar.

Animals↗
PubMed1976

Summary of the changes in the human female genital tract as a consequence of maternal diethylstilbestrol therapy.

The current evidence associating maternal ingestion of diethylstilbestrol (DES) with the subsequent appearance of clear-cell adenocarcinoma of the genital tract has been presented. Thus far, these cancers are rare among exposed females. DES, dienestrol, and hexestrol, all nonsteroidal synthetic estrogens, have been implicated. The tumors have appeared primarily in exposed subjects over the age of 14 yr with the median ranging from 18 to 19 yr. Nonneoplastic abnormalities have been observed commonly in the exposed, including vaginal adenosis, cervical erosion (ectropion), and transverse vaginal and cervical ridges. The highest incidence of vaginal adenosis was noted among those whose mothers began DES in early pregnancy, and no cases were observed among those whose mothers began treatment after the 18th wk. Current evidence suggests that these alterations as well as the carcinomas are of mullerian origin.

Adenocarcinoma↗