STEROID HORMONE FORMATION BY THE RAT OVARY.

1966 ◽  
Vol 51 (1) ◽  
pp. 131-139 ◽  
Author(s):  
Bernard F. Rice ◽  
Albert Segaloff
Keyword(s):  
Steroid Hormone ◽  
Ovarian Tissue ◽  
Female Rats ◽  
Male Rats ◽  
Corpora Lutea ◽  
Castrate Male ◽  
Rat Ovary ◽  
17 Hydroxyprogesterone ◽  
Hormone Formation

ABSTRACT Ovaries were transplanted to the spleens of castrate male rats. After 120 days, slices of ovarian tissue, composed predominantly of corpora lutea, were incubated in Krebs-Ringer bicarbonate medium containing 50 μc acetate-1-14C. Radioactive steroid formation was assessed quantitatively by reverse isotope dilution. The formation of radioactive progesterone and 20α-hydroxy-pregn-4-en-3-one was established. The formation of radioactive 3β-hydroxy-pregn-5-en-20-one, androst-4-ene-3,17-dione, 17-hydroxyprogesterone, testosterone, oestrone and 17β-oestradiol could not be established. It appears that the corpus luteum of the rat, induced by endogenous gonadotrophins, forms only progestins from acetate-1-14C. Contrary to results previously obtained with ovarian tissue transplanted to female rats, radioactive steroid formation in vitro appeared to be augmented by luteinizing hormone (NIH-LH-S1) added to the incubation flasks. Administration of human chorionic gonadotrophin (200 IU/day) for 5 days prior to autopsy did not enhance acetate-1-14C incorporation in vitro.

Effects of in vivo gonadal hormone environment on in vitro hGRF-40-stimulated GH release

1985 ◽  
Vol 249 (3) ◽  
pp. E276-E280 ◽  
Author(s):  
W. S. Evans ◽  
R. J. Krieg ◽  
E. R. Limber ◽  
D. L. Kaiser ◽  
M. O. Thorner
Keyword(s):  
Female Rats ◽  
Male Rats ◽  
Gonadal Hormone ◽  
Base Line ◽  
Pituitary Cells ◽  
Intact Male ◽  
Castrate Male ◽  
Basal Release

The effects of gender and the gonadal hormone environment on basal and stimulated growth hormone (GH) release by dispersed and continuously perifused rat anterior pituitary cells were examined. Cells from intact male and diestrus day 2 female rats and from castrate male rats either untreated or treated with testosterone (T) or 17 beta-estradiol (E2) were used. Basal GH release (ng/min per 10(7) cells; mean +/- SE) by cells from diestrus day 2 female rats was less than by cells from castrate rats treated with T (4.3 +/- 0.6 vs. 11.4 +/- 2.7, respectively; P less than 0.025). No other differences in basal release were detected. Concentration-response relationships were documented between human GH-releasing factor 40 (hGRF-40; 0.03-100 nM given as 2.5-min pulses every 27.5 min) and GH release. Mean (+/- SE) overall GH release (ng/min per 10(7) cells) above base line was greater by cells from intact male rats (496 +/- 92) than by cells from castrate (203 +/- 37.3; P less than 0.0001), castrate and T-treated (348 +/- 52.8; P = 0.008), or castrate and E2-treated (58.1 +/- 6.8; P less than 0.001) male rats or by diestrus day 2 rats (68.6 +/- 9.5; P = 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

STEROID HORMONE FORMATION BY THE RAT OVARY.

1967 ◽  
Vol 54 (3) ◽  
pp. 568-576 ◽  
Author(s):  
Bernard F. Rice ◽  
Albert Segaloff
Keyword(s):  
Ovarian Neoplasms ◽  
Steroid Hormone ◽  
Ovarian Neoplasm ◽  
Female Rats ◽  
Granulosa Cell Tumour ◽  
Dilution Technique ◽  
Hormone Synthesis ◽  
Ovarian Tumours ◽  
Rat Ovary ◽  
Hormone Formation

ABSTRACT Ovaries were transplanted to the spleens of spayed female rats. After 18 months, ovarian neoplasms had developed. Slices of two different ovarian tumours were incubated with 100 μc acetate-1-14C. Radioactive steroid hormone formation was assessed quantitatively by the reverse isotope dilution technique. Tissue from one ovarian neoplasm, considered to be a luteoma, formed radioactive progesterone and 20α-hydroxy-pregn-4-en-3-one. The formation of 3β-hydroxy-pregn-5-en-20-one, androst-4-ene-3,17-dione, testosterone, 3β-hydroxy-androst-5-en-17-one, 17-hydroxy-pregn-4-ene-3,20-dione, oestrone and 17β-oestradiol could not be established. No radioactive steroid hormone synthesis could be detected using granulosa cell tumour tissue.

scholarly journals Steroid Hormone Formation IN VITRO by Developing Corpora Lutea of the Rabbit Ovary

1977 ◽  
Vol 53 (8) ◽  
pp. 970-981
Author(s):  
Akira SUZUKI ◽  
Takahide MORI ◽  
Yasuhiko FUJITA ◽  
Toshio NISHIMURA
Keyword(s):  
Steroid Hormone ◽  
Corpora Lutea ◽  
Hormone Formation

scholarly journals Reproductive toxicity of triazole fungicides cyproconazole and epoxiconazole when exposed to male and female wistar rats during gametogenesis

2021 ◽  
Vol 54 (1) ◽  
pp. 52-61
Author(s):  
NR Shepelskaya ◽  
YaV Kolyanchuk
Keyword(s):  
Body Weight ◽  
Reproductive Toxicity ◽  
Reproductive Function ◽  
Female Rats ◽  
Male Rats ◽  
Corpora Lutea ◽  
Disruptive Effect ◽  
Male And Female ◽  
Two Samples ◽  
Adverse Effect Level

Aim. Studying the effect of generic pesticides cyproconazole (98 %) and two samples of epoxiconazole (epoxiconazole 1 — 95,75 % and epoxiconazole 2 — 98,7 %) on the reproductive system of male and female Wistar Han rats at the level of the organism when exposed during gametogenesis, identification and characterization of their hazard, as well as assessment of the risk of reproductive toxicity of these compounds. Materials and Methods. The test samples were administered daily (5 days a week) by oral gavage at doses of 0.2 and 2.0 mg/kg for cyproconazole and 0.5 and 2.0 mg/kg for epoxiconazoles during 11 weeks for males, and 10 weeks for females. Also, there were kept intact males and females, intended for crossover mating with experimental animals. After the end of the exposure, functional indicators of the state of the gonads and the ability of animals to reproduce offspring were studied. The duration and the frequency of each stage of the estrous cycle in female rats and the number of motile sperm, the total amount of sperm and the number of abnormal forms of germ cells of the male rats were studied. The reproductive function state in females was evaluated on day 20th of pregnancy. Thereby the number of corpora lutea in the ovaries, number of alive, dead and resorbed foetuses and embryos, the foetus weight, total weight of litters were registered. The studies were carried out in accordance with the recommendations of the Bioethics Commission and the Centre’s standard operating procedures, developed in accordance with the recommendations and requirements of Good Laboratory Practice (GLP). Conclusions. Test substances at a maximum dose of 2.0 mg/kg of body weight have reproductive toxicity and endocrine-disruptive effect, exerting a significant antiandrogenic effect on males and antiestrogenic effect on female rats. No-observed-adverse-effect-level (NOАEL) for gonadal and reproductive toxicity for male and female Wistar Han rats were established. They are 0.2 mg/kg body weight for cyproconazole and 0.5 mg/kg body weight for epoxiconazole. Key Words: azole fungicides, cyproconazole, epoxiconazole, reproductive toxicity, antiandrogenic and antiestrogenic effects, Wistar Han rats.

IN VITRO STUDIES ON CARBOHYDRATE METABOLISM IN THE VITAMIN-B6-DEPRIVED RAT

1955 ◽  
Vol 33 (1) ◽  
pp. 562-567
Author(s):  
John R. Beaton
Keyword(s):  
Carbohydrate Metabolism ◽  
Vitamin B6 ◽  
Glucose Utilization ◽  
Female Rats ◽  
Male Rats ◽  
Vitamin B ◽  
Significant Difference ◽  
Aldolase Activity ◽  
Food Consumed

Following earlier studies on carbohydrate metabolism in the vitamin-B6-deprived rat, in vitro investigations have been carried out. In all cases, comparisons were made between tissues from vitamin-B6-deprived and pair-fed control animals so that differences in the amount of food consumed would not affect the interpretation of experimental results. No significant difference was found in glucose utilization by muscle nor in liver cytochrome oxidase activity. Liver aldolase activity was significantly decreased and the activity of plasma alkaline phosphatase was significantly increased in the vitamin-B6-deprived rats. In vitamin-B6-deprived female rats, but not male rats, liver catalase activity was significantly increased. These results are discussed in the light of earlier observations indicating disturbances in carbohydrate metabolism in the vitamin-B6-deprived rat.

STUDIES ON FACTORS INFLUENCING THE ACUTE TOXICITY OF MALATHION AND MALAOXON IN RATS

1967 ◽  
Vol 45 (4) ◽  
pp. 621-631 ◽  
Author(s):  
Jules Brodeur ◽  
K. P. DuBois
Keyword(s):  
Enzymatic Activity ◽  
Young Male ◽  
Female Rats ◽  
Male Rats ◽  
Age Difference ◽  
Adult Males ◽  
Organophosphate Insecticide ◽  
In Vitro Measurements ◽  
Immature Rats

A study was undertaken to investigate the mechanisms responsible for the higher susceptibility of immature rats to the organophosphate insecticide malathion. In vitro measurements of the activity of malathionase in the tissues of rats, at various time intervals after birth, indicated that the livers of immature rats detoxify the insecticide at a much slower rate than do the livers of adult animals. Evidence was obtained which showed that prolonged administration of testosterone causes a significant increase of the enzymatic activity in the livers of castrated young male rats and adult female rats. On the other hand, castration interferes with the maintenance of normal levels of malathionase in adult males and partially prevents the development of the activity in weanlings. Estradiol decreases the enzymatic activity in adult males. It appears, therefore, that the age difference in the susceptibility of rats to malathion might be due, to a large extent, to a slower rate of inactivation of the insecticide by the livers of immature animals. The results obtained also indicate that the sex hormones play an important role in the development and maintenance of normal levels of the enzyme system involved in the degradation of malathion in the livers of rats.

THE ROLE OF THE ADRENAL GLAND IN THE CONTROL OF AMINO ACID INCORPORATION INTO PROTEIN OF ISOLATED RAT LIVER MICROSOMES

1960 ◽  
Vol 21 (2) ◽  
pp. 177-189 ◽  
Author(s):  
A. KORNER
Keyword(s):  
Amino Acid ◽  
Rat Liver ◽  
Liver Microsomes ◽  
Female Rats ◽  
Male Rats ◽  
Rat Liver Microsomes ◽  
Hypophysectomized Rats ◽  
Normal Rat ◽  
Secondary Result

SUMMARY 1. Microsomes, isolated from rat liver a day after adrenalectomy, incorporate more radioactive amino acid into their protein in vitro than microsomes from normal rat liver. This enhanced rate of incorporation progressively declines with time after adrenalectomy until it reaches a plateau level which is below the normal rate of incorporation. 2. Following adrenalectomy microsomes isolated from liver of male rats show a greater rise in incorporating ability than those from liver of female rats, and maintain it longer. 3. Most of the increased incorporation observed in the in vitro system soon after adrenalectomy of the rat, and most of the decreased incorporation observed in rats adrenalectomized for some time, results from alterations in the microsomes which change their ability to incorporate activated amino acids into proteins. 4. Treatment of rats with cortisol acetate results in an increase in the ability of liver microsomes to incorporate amino acid into protein. This heightened incorporating ability is probably a secondary result of the breakdown of extrahepatic tissue protein which is stimulated by cortisol. 5. Somewhat similar responses to acute adrenalectomy and to treatment with cortisol were found in hypophysectomized rats. 6. The protein anabolic response of adrenalectomized rats to treatment with insulin, and of adrenalectomized-hypophysectomized rats to treatment with insulin or growth hormone, is greater than that shown by rats which possess adrenal glands.

Involvement of cGMP in LHRH-stimulated gonadotropin release.

1978 ◽  
Vol 235 (6) ◽  
pp. E586 ◽  
Author(s):  
Z Naor ◽  
C P Fawcett ◽  
S M McCann
Keyword(s):  
Mechanism Of Action ◽  
Female Rats ◽  
Male Rats ◽  
Camp Content ◽  
Luteinizing Hormone Releasing Hormone ◽  
Gonadotropin Release ◽  
Male And Female Rats ◽  
The Relationship ◽  
Stimulation Of

Anterior pituitary content of cyclic AMP (cAMP) and cyclic GMP (cGMP) has been measured during stimulation of gonadotropin release by luteinizing-hormone-releasing hormone (LHRH) in vitro to gain more information concerning the relationship between the mechanism of action of LHRH and cyclic nucleotides. During the increased gonadotropin release obtained by incubation by hemipituitaries with LHRH (0.25--25 X 10(-9) M) for 180 min, the glands taken from both male and female rats exhibited increased cGMP content, whereas cAMP content rose only in those taken from male rats. The increase in cGMP content was observed after only 2 min in the presence of LHRH (5 X 10(-9) M) and prior to augmented gonadotropin release. The increase in cAMP content in the male glands was detectable only after 60 min of incubation. These results suggest that cGMP might be involved in the mechanism of action of LHRH.

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