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PubMed1976

[Preovulatory changes of steroidogenesis in isolated rabbit follicles (author's transl)].

In an attempt to investigate the effect of ovulating hormone on the steroidogenesis of mature follicles in the course of ovulation, transitory changes of steroidogenesis in isolated rabbit follicles have been studied at several intervals after injection of an ovulatory dose of human chorionic gonadotropin (hCG). Five to ten follicles of approximately 1-2 mm in diameter were isolated from ovaries of a mature rabbit (2.5-3.0 kg) under streomicroscope, before and at the 3rd, 6th, 9th and 12th hours after intravenous injection of of 100 IU/kg of hCG. Follicles were incubated with 100 muCi of acetate-1-14C in 2 ml of Krebs-Ringer bicarbonate buffer (pH 7.4) at 37 degrees C for 3 hours under 95% oxygen plus 5% carbon dioxide. Each incubation was terminated by quick freezing and stored forzen at -20 degrees C until eighty follicles had been collected for each time period before commencement of analysis. Incorporation of radioactive acetate into pregnenolone, 17-hydroxypregnenolone, progesterone, 17-hydroxyprogesterone., 20 alpha-dihydroxyprogesterone, dehydroepiandrosterone, androstenedione, testosterone, estrone and estradiol-17beta were analysed by the reverse dilution technique and identified in radiochemically pure form by recrystallization to constant specific activities. The steroidogenic activity of the follicles was evaluated by overall as well as fractionated incorporations. A peak in the overall incorporation of 14C- acetate into the ten steroids at the 3rd hour after hCG injection, followed by gradual decrease up to the 9th hour was observed. The incorporation decreased markedly to a minimum level at the 12th hour after hCG injection, which was below the level of preinjection control. Comparable quantitative fluctuations were found with the fractionated incorporation of 14C-acetate into the C21 and C18 steroids in the time sequence following hCG injection. However, the fractionated incorporation into C19 steroids reached to a maximum at the 6th hour after hCG injection. 5istribution patterns of incorporation among the individual steroids were varied at each interval of time. In the non-injected control, mature follicles synthesized predominantly estradiol-17beta, testosterone and androstenedione. Divergent steroids were formed from radioactive acetate at the 3rd hour after hCG injection. These included porgestogen, androgen and estrogen, but pregnenolone and 17hydroxyprogesterone were the two principal steroids produced. There was no essential difference in the steroidogenic patterns between the 6th and 9th hour, the major products being C21 and C19 steroids such as pregnenolone, 17hydroxyprogesterone, dehydroipiandrosterone and testosterone. The three androgens were the major steroids formed at the 12th hour after hCG injection. Thus the chages in the steroidogenic profile of the follicle was obvious in the course of ovulation. The basis of qualitative changes in follicular steroidogenesis during the process of ovulation have been discussed in connection with an accompanying effect of an ovulatory dose of hCG.

Acetates↗
PubMed1976

Estrogens in maternal plasma following intraamniotic injection of (3H)-dehydroepiandrosterone-sulfate in midpregnancy.

In 4 patients with normal pregnancies between the 18th and 20th week of gestation (3H7alpha)-dehydroepiandrosterone-sulfate ([H]-DHEA-S) was injected intraamniotically. Maternal venous blood was drawn before and at regular intervals for 240 minutes after DHEA-injection. Thereafter, legal abortion was performed by intraamniotic instillation of prostaglandine. The conjugated steroids were hydrolyzed enzymatically and the total steroids were isolated and identified. The following labelled metabolites were determined quantitatively: Estriol (e3, estradiol-17beta (E2-17beta), estrone(E1), 16alpha-hydroxy-estrone, (16alpha-OH-DHEA), ALPHA4-androstenedione (AD) and testosterone (T). The maximal increase of all estrogen fractions in matermal plasma occurred 120-180min after intraamniotic injection of the precursor. The most prominent rise of the C18-steroids could be shown for estriol. 60-70% of all metabolites were C16-hydroxylated.

Amnion↗
PubMed1977

Steroid and prostaglandin concentrations in the plasma of pregnant ewes during infusion of adrenocorticotrophin or dexamethasone to intact or hypophysectomized foetuses.

Catheters were implanted into 16 ewes and their foetuses between days 110 and 124 of gestation. Hypophysectomy was attempted in eight of these foetuses. Continuous infusion of synthetic ACTH (10 microgram/h) or dexamethasone (1mg/24 h) into the foetus, starting between days 124 and 129, induced premature parturition. The concentration of progesterone in the maternal peripheral plasma decreased before parturition in all animals while the level of oestradiol increased in ewes with intact foetuses or in those in which hypophysectomy was incomplete. When hypophysectomy was complete, no increase in the maternal level of oestradiol occurred before delivery. The concentration of 13,14-dihydro-15-oxo-prostaglandin F2alpha increased in the peripheral plasma of ewes with intact or hypophysectomized foetuses infused with ACTH. It is suggested that an intact foetal pituitary gland is required for the rise in the level of oestrogen prepartum, but that this rise is not essential for increased prostaglandin production of parturition.

Adrenocorticotropic Hormone↗
PubMed1976

Estrogen-binding parameters of cytoplasmic and nuclear receptors in an established rat endometrial cell line and tumor.

We have consistently found receptors for estradiol in both the cytosol and nuclear extracts of a rat endometrial cell line and in transplantable tumors derived from this cell line. The equilibrium dissociation constants (Kd) and the rate constants for the receptor-estradiol interaction in these cells and tumors did not differ significantly from those of the cytosol receptor in the rat uterus. A mean Kd of 3 x 10(-10) M with a rate of association (Ka) of 3 x 10(5) M-1sec-1 and a rate of dissociation (Kd) of 1.5 x 10(-5) sec-1 were obtained for nuclear and cytosol receptors for both tumors and cells. For uterine cytosol, a Kd of 8 x 10(-10) M, ka = 2.8 x 10(5) M-1sec-1 and kd = 1 x 10(-5) sec-1 were obtained. Although no differences were seen in equilibrium and kinetic parameters for estradiol-17beta binding between the nuclear and cytosol receptors of tumors and cells, an apparent difference in the relative affinities of nuclear and cytosol receptors for estrone was detected. This suggests that the binding site in nuclear receptors may have been modified. Implications of this observation with regard to receptor translocation and the mechanism of action of sex hormones are being considered.

Animals↗
PubMed1992

Hormone levels and anogenital swelling of female chimpanzees as a function of estrogen dosage in a combined oral contraceptive.

A combined oral contraceptive consisting of ethinyl estradiol (EE2) in three dosages (50, 100, and 400 micrograms) and norethindrone (0.5 mg) was given to female chimpanzees to determine the effect on endogenous sex hormone levels and anogenital swelling. Serum levels of EE2 increased with increasing dosages of EE2, estradiol decreased, and luteinizing hormone, progesterone and testosterone were maintained at approximately midfollicular phase levels. Urinary levels of EE2 glucuronide increased with the increasing dosages of EE2, whereas estrone and pregnanediol glucuronide were essentially undetectable. The cyclic increase in female anogenital swelling was abolished when the norethindrone was combined with 50 micrograms of EE2 and relatively constant and low levels of swelling were recorded. Relatively constant but successively higher levels of swelling were recorded when the norethindrone was combined with the higher dosages of EE2. These effects of oral contraceptives on female genital tissues are relevant to our laboratory studies of sexual behavior in chimpanzees given oral contraceptives and could also have implications for women taking oral contraceptives.

Anal Canal↗
PubMed1976

Estrogens and endometrial cancer: aspects of etiology and survival rate.

With a clinical study it could be demonstrated, that the frequency of diabetes hypertension, estrogen effect in the vaginal smear and proliferative changes of the endometrium was significantly higher in patients with endometrial cancer than in a control group (p less than or equal to 0.001). Obesity was also significantly more frequent (0.02 less than p less than 0.01). In vitro studies demonstrated a significantly higher aromatization of androstendione to estrone in adipose tissue of endometrial cancer patients (p less than 0.01), indicating etiologic correlations between endometrial cancer and extraglandular estrone production. An additional clinical study indicated a better 5-years-survival rate if parameters, indicating endogenous estrogen effect were present.

Adipose Tissue↗
PubMedDate not supplied

[Steroidogenic function of the intra-arterial trophoblast in the rat. Ultrastructural, histoenzymologic and biochemical data].

The ultrastructural study of the intra-arterial trophoblast has revealed in the pregnant Rat a steroidogenic activity which has been confirmed by histoenzymologic observations (presence of delta 5-3 beta-HSDH and 17 beta-HSDH). At the 15th day postcoitum an in vitro investigation upon the metabolism of steroid hormone precursors suggests that the steroids (oestrogens, progestogens and androgens) secreted by the intra-arterial trophoblast have a local action upon the wall of the uterine placental arteries and are actively concerned with an important part upon the utero-placental hemodynamic as a whole.

Androstenedione↗
PubMed1976

[Concentration of estrone, estradiol and estriol in the blood of pregnant sheep after induction of estrus with chlormadinone acetate and medroxyprogesterone acetate].

The radioisotopic method of 131J-labelled albumin was employed to determine the distribution of acidic proteinase activity in some organs and tissues of chickens. The highest enzymatic activities were found in intestine wall, in pancreas, and in liver. Considerably lower activities were ascertained in kidneys, brain, lungs, and heart. The different proportions of these enzymes in homogenates and supernatant fractions (106 000 g) testify to a lack of uniformity in the solubility of cathepsins in the organs tested. The tested organs, with the exception of pancreas, did not show any enzymatic activity of neutral proteinases.

Animals↗
PubMed1977

[Diagnosis and monitoring of endangered early pregnancies with determination of oestrone, oestradiol 17beta, oestriol, progesterone and HPL in plasma and the pregnancy test in graduated dilutions of urine (author's transl)].

Unconjugated oestrone (Oe1), oestradiol-17beta (Oe2), oestriol (Oe3), progesterone (P) and HPL in plasma were determined by radioimmunoassay and the immunological pregnancy-test in urine was carried out in 70 patients with normal pregnancy or imminent abortion from 4th-20th week of gestation. Oe2 and HPL showed the most pronounced rises, Oe3 increased especially after the first trimester. In cases with abortion symptoms and poor prognosis Oe2 and HPL gave the most reliable results concerning the endocrin function of early normal pregnancy. Oe1- and P-values in normal pregnancy did not differ so clearly from concentrations observed during normal menstrual cycles and were thus of less value. The pregnancy-test was positive (greater than 1000 IU/1) even in most cases of dead pregnancy and therefore not reliable. With increasing production of oestrogen precursors in the fetal adrenal cortex after the first trimester determination of Oe3 becomes more important. In cases with abortion symptoms in early pregnancy and subsequent normal development, plasma Oe2- and Oe3- values represented best criteria for a prognosis. -- For the diagnosis and control of the endangered early pregnancy we recommend, as a consequence of this study, determination of Oe2 up to the 13th week of pregnancy and thereafter Oe3 in maternal plasma.

Estradiol↗
PubMed1977

Inhibitory effects of sexual steroidal hormones on the responses of the isolated guinea-pig lleum to acetylcholine and histamine.

Six sexual steroidal hormones (progesterone, pregnenolone, testosterone, ethinyl-oestradiol, oestriol and oestrone) inhibit acetylcholine- and histamine-induced contractions of the isolated guinea-pig ileum. Different degrees of inhibitory capacity were found. High concentrations of PGE1 and F2alpha reverse some of these inhibitions. This reversal seems to be non-specific and probably related to sensitization of the ileal smooth muscle by prostaglandins. The inhibitory action of sexual steroids might be non-specific as well. But a "corticoid-like" effect cannot be excluded.

Acetylcholine↗