SOME FACTORS INFLUENCING THE VITALIZATION OF THE OVARIAN GRAFT AND THE PRODUCTION OF SEX HORMONES IN THE MALE RAT

Endocrinology ◽  
1937 ◽  
Vol 21 (2) ◽  
pp. 260-267 ◽  
Author(s):  
CARROLL A. PFEIFFER
Keyword(s):  
Sex Hormones ◽  
Male Rat ◽  
Factors Influencing ◽  
Ovarian Graft

scholarly journals Male-specific suppression of hepatic microsomal UDP-glucuronosyl transferase activities toward sex hormones in the adult male rat administered bisphenol A

2002 ◽  
Vol 368 (3) ◽  
pp. 783-788 ◽  
Author(s):  
Noriaki SHIBATA ◽  
Junya MATSUMOTO ◽  
Ken NAKADA ◽  
Akira YUASA ◽  
Hiroshi YOKOTA
Keyword(s):  
Bisphenol A ◽  
Mrna Expression ◽  
Sex Hormones ◽  
Adult Male ◽  
Endocrine Disruptor ◽  
Liver Microsomes ◽  
Female Rats ◽  
Male Rats ◽  
Male Rat ◽  
Blotting Analysis

Various adverse effects of endocrine disruptors on the reproductive organs of male animals have been reported. We found that UDP-glucuronosyltransferase (UGT) activities towards bisphenol A, testosterone and oestradiol were significantly decreased in liver microsomes prepared from adult male Wistar rats administered with the endocrine disruptor bisphenol A (1mg/2 days for 2 or 4 weeks). However, suppression of the transferase activities was not observed in female rats, even after bisphenol A treatment for 4 weeks. Diethylstilbestrol, which is well known as an endocrine disruptor, had the same effects, but p-cumylphenol had no effect on UGT activities towards sex hormones. Co-administration of an anti-oestrogen, tamoxifen, inhibited the suppression of the transferase activities by bisphenol A. Western blotting analysis showed that the amount of UGT2B1, an isoform of UGT which glucuronidates bisphenol A, was decreased in the rat liver microsomes by the treatment. Northern blotting analysis also indicated that UGT2B1 mRNA in the liver was decreased by bisphenol A treatment. The suppression of UGT activities, UGT2B1 protein and UGT2B1 mRNA expression did not occur in female rats. The results indicate that bisphenol A treatment reduces the mRNA expression of UGT2B1 and other UGT isoforms that mediate the glucuronidation of sex hormones in adult male rats, and this suggests that the endocrine balance may be disrupted by suppression of glucuronidation.

THE EFFECT OF SEX HORMONES ON THE ADRENAL GLAND OF THE MALE RAT

1958 ◽  
Vol 17 (2) ◽  
pp. 107-113 ◽  
Author(s):  
D. GOMPERTZ
Keyword(s):  
Adrenal Gland ◽  
Sex Hormones ◽  
Opposite Effect ◽  
Adrenal Glands ◽  
Male Rat ◽  
Adrenocorticotrophic Hormone

SUMMARY Oestradiol dipropionate enhances the effect of both endogenous and exogenous adrenocorticotrophic hormone (ACTH) on the weight of the adrenal glands of the male rat. Methyl testosterone has the opposite effect. It is concluded that sex hormones exert their effect by modifying both hypophysial secretion of ACTH and adrenocortical sensitivity to ACTH.

Effect of sex hormones on blood pressure and vascular connective tissue in castrated and noncastrated male rats

1977 ◽  
Vol 232 (6) ◽  
pp. H617-H621 ◽  
Author(s):  
G. M. Fischer ◽  
M. L. Swain
Keyword(s):  
Blood Pressure ◽  
Connective Tissue ◽  
Systolic Blood Pressure ◽  
Sex Hormones ◽  
Intramuscular Injection ◽  
Marked Effect ◽  
Male Rats ◽  
Male Rat ◽  
Total Collagen

Aortic collagen and elastin were quantitated in three groups of castrated and two groups of noncastrated male rats treated by intramuscular injection for 3 wk with oil, testosterone, or estradiol. The greatest differences were found between the castrated rats receiving testosterone and those receiving estradiol, the estradiol-treated rats having significantly lower total collagen, percent collagen, total elastin, and collagen/elastin (C/E), and higher percent elastin than those rats receiving testosterone. In noncastrated rats, administration of estradiol resulted in significantly lower total collagen, percent collagen, total elastin, and C/E. Systolic blood pressure was highest in rats receiving testerone and lowest in rats receiving estradiol. It is concluded that 1) estradiol in the presence or absence of testosterone decreases total accumulation of vascular connective tissue and alters the proportions of collagen and elastin so that the vessel is more distensible, 2) testosterone has an opposite but less marked effect than estradiol on vascular connective tissue, and 3) estradiol and testosterone alter blood pressure in opposite directions in the male rat.

scholarly journals Effect of age, gonadectomy and hypophysectomy on mitochondrial hydroxylation of vitamin D3 (cholecalciferol) and of 5β-cholestane-3α,7α,12α-triol in female and male rat liver

1988 ◽  
Vol 251 (2) ◽  
pp. 475-481 ◽  
Author(s):  
K Saarem ◽  
J I Pedersen
Keyword(s):  
Sex Hormones ◽  
Rat Liver ◽  
Vitamin D3 ◽  
Female Rats ◽  
Male Rats ◽  
Male Rat ◽  
Side Chain ◽  
Hydroxylase Activity ◽  
Testosterone Treatment ◽  
Alpha 7

In a previous study we found that liver mitochondrial side-chain hydroxylation of vitamin D3 (cholecalciferol) and of 5 beta-cholestane-3 alpha,7 alpha,12 alpha-triol was higher in female than in male rats [Saarem & Pedersen (1987) Biochem. J. 247, 73-78]. The present paper describes the effects of age, gonadectomy and hypophysectomy on these activities. The sex difference became manifest above the age of 7 weeks. Ovariectomy and/or injection of oestradiol valerate had no effect on the hydroxylase activities in adult females. Castration increased, and subsequent testosterone treatment decreased, the hydroxylase activities in adult males. Hypophysectomy had no effect in females, but increased the hydroxylase activities in males. Testosterone treatment had no effect in hypophysectomized females or males. Injection of oestradiol valerate had no effect on the hydroxylase activities in hypophysectomized females. In hypophysectomized males this treatment had no effect on the vitamin D3 25-hydroxylase activity, but decreased the C27-steroid 27-hydroxylase activity in males. Microsomal 1 alpha-hydroxyvitamin D3 25-hydroxylase activity was lower in females than in males in all age groups. Castration or hypophysectomy decreased the activity in male rats. It is concluded that, in adult female rats, the mitochondrial side-chain hydroxylation of vitamin D3 and of 5 beta-cholestane-3 alpha,7 alpha,12 alpha-triol is independent of sex hormones. In males these activities are regulated by influence of sex hormones on the hypophysis, probably by the presence of androgens in the neonatal period. Different effects on the two hydroxylases indicate the presence of at least two different cytochromes P-450 in rat liver mitochondria.

Binding of sex hormones by male rat liver microsomes

1982 ◽  
Vol 16 (3) ◽  
pp. 437-446 ◽  
Author(s):  
Morio Yamada ◽  
Hideki Miyaji
Keyword(s):  
Sex Hormones ◽  
Rat Liver ◽  
Liver Microsomes ◽  
Male Rat ◽  
Rat Liver Microsomes

scholarly journals Sex differences in the hydroxylation of cholecalciferol and of 5 β-cholestane-3 α, 7 α, 12 α-triol in rat liver

1987 ◽  
Vol 247 (1) ◽  
pp. 73-78 ◽  
Author(s):  
K Saarem ◽  
J I Pedersen
Keyword(s):  
Sex Hormones ◽  
Rat Liver ◽  
Female Rats ◽  
Regulatory Control ◽  
Male Rats ◽  
Male Rat ◽  
Female Rat ◽  
Significant Difference ◽  
Alpha 7 ◽  
Rat Livers

The effect of sex hormones on hydroxylation of cholecalciferol (‘vitamin D3’) and of 5 beta-cholestane-3 alpha, 7 alpha, 12 alpha-triol has been investigated in female- and male-rat livers. The mitochondrial cholecalciferol 25-hydroxylase and C27-steroid 27-hydroxylase activities were respectively 4.6- and 2.7-fold higher in female- than in male-rat livers. The microsomal 1 alpha-hydroxycholecalciferol 25-hydroxylase was 2.8-fold higher in male- than in female-rat liver. No significant difference was found in the microsomal 25-hydroxylation of 5 beta-cholestane-3 alpha, 7 alpha, 12 alpha-triol. Liver microsomes (microsomal fractions) from male, but not from female, rats also catalysed 1-hydroxylation of 5 beta-cholestane-3 alpha, 7 alpha, 12 alpha-triol. Injection of testosterone into female rats decreased the mitochondrial cholecalciferol 25-hydroxylase and C27-steroid 27-hydroxylase activities, but not to a statistically significant extent. Testosterone treatment had no effect on the microsomal hydroxylases in female-rat liver. Injection of oestradiol valerate to male rats resulted in increased activities of both mitochondrial hydroxylases to the same levels as those of control females, while the microsomal enzyme activities decreased. The present results indicate that sex hormones exert a regulatory control on the mitochondrial cholecalciferol 25-hydroxylase and C27-steroid 27-hydroxylase activities.

Modulation of aortic vascular reactivity by sex hormones in a male rat model of metabolic syndrome

Life Sciences ◽  
2007 ◽  
Vol 80 (23) ◽  
pp. 2170-2180 ◽  
Author(s):  
Israel Pérez Torres ◽  
Mohammed El Hafidi ◽  
José Zamora-González ◽  
Oscar Infante ◽  
Roberto Chavira ◽  
...  
Keyword(s):  
Metabolic Syndrome ◽  
Sex Hormones ◽  
Rat Model ◽  
Vascular Reactivity ◽  
Male Rat ◽  
Aortic Vascular Reactivity

Factors influencing adhesive bonding at the bone/implant interface

1992 ◽  
Vol 50 (2) ◽  
pp. 1114-1115
Author(s):  
Julie A. Martini ◽  
Robert H. Doremus
Keyword(s):  
Electron Microscopy ◽  
Adhesive Bonding ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Bone Implant ◽  
Factors Influencing ◽  
Lr White ◽  
Transmission Electron ◽  
New Zealand White Rabbits ◽  
Scanning Electron

Tracy and Doremus have demonstrated chemical bonding between bone and hydroxylapatite with transmission electron microscopy. Now researchers ponder how to improve upon this bond in turn improving the life expectancy and biocompatibility of implantable orthopedic devices.This report focuses on a study of the- chemical influences on the interfacial integrity and strength. Pure hydroxylapatite (HAP), magnesium doped HAP, strontium doped HAP, bioglass and medical grade titanium cylinders were implanted into the tibial cortices of New Zealand white rabbits. After 12 weeks, the implants were retrieved for a scanning electron microscopy study coupled with energy dispersive spectroscopy.Following sacrifice and careful retrieval, the samples were dehydrated through a graduated series starting with 50% ethanol and continuing through 60, 70, 80, 90, 95, and 100% ethanol over a period of two days. The samples were embedded in LR White. Again a graduated series was used with solutions of 50, 75 and 100% LR White diluted in ethanol.

Factors Influencing Electrophysiologic Responsivity in Normal Adults

1965 ◽  
Vol 8 (4) ◽  
pp. 323-347
Author(s):  
Robert Goldstein ◽  
Benjamin RosenblÜt
Keyword(s):  
Conditioned Stimulus ◽  
White Light ◽  
Pure Tone ◽  
Alpha Rhythm ◽  
White Women ◽  
White Men ◽  
Inverse Relation ◽  
Factors Influencing ◽  
Electrodermal Responses ◽  
Normal Adults

Electrodermal and electroencephalic responsivity to sound and to light was studied in 96 normal-hearing adults in three separate sessions. The subjects were subdivided into equal groups of white men, white women, colored men, and colored women. A 1 000 cps pure tone was the conditioned stimulus in two sessions and white light was used in a third session. Heat was the unconditioned stimulus in all sessions. Previously, an inverse relation had been found in white men between the prominence of alpha rhythm in the EEG and the ease with which electrodermal responses could be elicited. This relation did not hold true for white women. The main purpose of the present study was to answer the following questions: (1) are the previous findings on white subjects applicable to colored subjects? (2) are subjects who are most (or least) responsive electrophysiologically on one day equally responsive (or unresponsive) on another day? and (3) are subjects who are most (or least) responsive to sound equally responsive (or unresponsive) to light? In general, each question was answered affirmatively. Other factors influencing responsivity were also studied.

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