Estrogen and prothrombin synthesis: effect of estrogen on absorption of vitamin K1

1977 ◽  
Vol 232 (1) ◽  
pp. H12-H17 ◽  
Author(s):  
D. W. Jolly ◽  
C. Craig ◽  
T. E. Nelson
Keyword(s):  
Female Rats ◽  
Male Rats ◽  
Thoracic Duct Lymph ◽  
Albino Rats ◽  
Vitamin K1 ◽  
Intact Male ◽  
Deficient Diet ◽  
Castrate Male ◽  
Male And Female ◽  
Male And Female Rats

Intact male and female albino rats fed a vitamin K-deficient diet develop a plasma prothrombin-proconvertin deficiency. Male rats respond with a precipitous drop to approximately 20–30% of normal plasma levels within 2–5 days, whereas female rats respond at a slower rate. Ethynylestradiol, 5–10 mug/day, or castration, reduces the progressive decline of plasma prothrombin-proconvertin seen in nonsupplemented intact male rats. The response of castrate females differs little from the response of intact females. Ethynylestradiol, 5–10 mug/day, affects both castrate males and females similarly, limiting the prothrombin-proconvertin decrease to about 13% below control value after 14 days. Intestinal absorption of vitamin K1 measured in the thoracic duct lymph of pentobarbital-anesthetized castrate male and female rats was shown to increase significantly after estrogen treatment. Estrogen-treated castrate male and female rats absorbed 25.8 mug and 11.8 mug vitamin K1, respectively. Nontreated control castrate male and female rats absorbed 0.0 mug and 1.2 mug, respectively, during a 240-min collection period. Use of radioactive vitamin K1 in similar experiments confirmed these results. Estrogen-treated castrate males absorbed vitamin K1 at the rate of 30-40 mug/g lymph whereas nontreated control males absorbed only about 6 mug/g lymph.

LIVER GLUCURONIDASE ACTIVITY OF RATS IN VARIOUS EXPERIMENTAL STATES

1953 ◽  
Vol 31 (1) ◽  
pp. 18-40 ◽  
Author(s):  
Jules Tuba
Keyword(s):  
Virgin Female ◽  
Female Rats ◽  
Male Rats ◽  
Normal Male ◽  
Significant Elevation ◽  
Castrate Male ◽  
Male And Female ◽  
Glucuronidase Activity ◽  
Male And Female Rats ◽  
Hormonal Imbalance

Liver glucuronidase activity was studied in male and female rats with regard to the effect of a number of experimental factors. Virgin female and breeder female rats had significantly higher levels of the liver enzyme than males. Breeding and lactation stimulated production of liver glucuronidase and activity fell towards male values in females which had passed the breeding age. Castration of males or females had no significant effect on the enzyme. A highly significant elevation of liver glucuronidase resulted from injection of oestradiol dipropionate into castrate male rats, while testosterone dipropionate had no effect. Neither hormone affected activity of the enzyme when injected into normal male or female rats. Levels of liver glucuronidase in diabetic male rats were elevated about 50% above normal, and these statistically significant increases are assumed to be related to some hormonal imbalance

INVOLVEMENT OF INHIBIN IN THE REGULATION OF FOLLICLE-STIMULATING HORMONE CONCENTRATIONS IN PREPUBERTAL AND ADULT, MALE AND FEMALE RATS

1980 ◽  
Vol 86 (1) ◽  
pp. 79-92 ◽  
Author(s):  
W. P. HERMANS ◽  
E. C. M. VAN LEEUWEN ◽  
M. H. M. DEBETS ◽  
F. H. DE JONG
Keyword(s):  
Follicle Stimulating Hormone ◽  
Female Rats ◽  
Male Rats ◽  
Intact Male ◽  
Adult Rats ◽  
Physiological Factor ◽  
Male And Female ◽  
Male And Female Rats ◽  
Pituitary Secretion ◽  
Fast Acting

Administration of steroid-free bovine follicular fluid (bFF), containing inhibin-like activity, depressed levels of FSH measured 4 h after injection in intact adult and 35-day-old female rats, but not in younger females. Suppression of FSH was also observed in intact male rats, aged 55 days, but not in older and younger male rats. Eight hours after injection of bFF, FSH levels were depressed in 15-day-old and older immature and adult rats of both sexes. Male and female rats, gonadectomized 2 days earlier, responded similarly to bFF treatment as did the intact animals. In a second experiment it was found that the rise of FSH levels, occurring within 8 h of gonadectomy, decreased with age in male and increased with age in female rats. Steroid treatment was found to prevent the rise in FSH levels partially in 15-day-old male and completely in 25-day-old female rats, whereas treatment with bFF was fully effective in blocking the FSH rise in both immature and adult rats of both sexes. It is concluded that inhibin might be a major physiological factor in a fast-acting control of FSH concentrations from at least the age of 25 days onwards in female rats. In male rats its physiological significance might be limited to the prepubertal period, despite the fact that pituitary secretion of FSH is suppressed by exogenous inhibin-like activity at all ages studied.

EFFECTS OF TESTOSTERONE ON PITUITARY CORTICOTROPHIN AND ADRENAL STEROID SECRETION IN MALE AND FEMALE RATS

1963 ◽  
Vol 43 (4) ◽  
pp. 601-608 ◽  
Author(s):  
Julian I. Kitay
Keyword(s):  
Plasma Corticosterone ◽  
Female Rats ◽  
Male Rats ◽  
Intact Male ◽  
Male And Female ◽  
Adrenal Steroid ◽  
Adrenal Steroidogenesis ◽  
Male And Female Rats

ABSTRACT Administration of a depot testosterone preparation to male and female rats resulted in no change in body or pituitary weight in either sex. Pituitary corticotrophin content was unaltered in male animals but was reduced in females. Adrenal weights and adrenal RNA and DNA contents were decreased in both sexes. Plasma corticosterone concentrations were unaffected in males but were reduced in female rats after stress or corticotrophin injection. Hepatic reduction of ring A in vitro and biological half-life of corticosterone in vivo were unchanged in male animals but impaired in females. Testosterone administration to intact male rats significantly increased adrenal steroidogenesis measured in vitro. A significant decrease in steroid production was found in intact females but increased steroidogenesis was observed in adrenals from testosterone-treated oophorectomized animals. No effect was obtained following addition of testosterone directly in vitro. The data suggest that testosterone leads both to diminution of corticotrophin secretion and enhancement of adrenal steroid secretory capacity. In intact female rats, these effects are complicated by suppression of oestrogen secretion, the effects of which have been reported previously.

scholarly journals Effect of Ashwagandharishta on the lipid profile of male and female rats

2021 ◽  
Vol 9 (1-2) ◽  
pp. 59-68
Author(s):  
Tasmina Rahman ◽  
Mohammad Salahuddin Bhuiya ◽  
Rakib Hasan ◽  
MSK Choudhuri
Keyword(s):  
Lipid Profile ◽  
Serum Cholesterol ◽  
Density Lipoprotein ◽  
Serum Triglyceride ◽  
Female Rats ◽  
Male Rats ◽  
Albino Rats ◽  
High Dose ◽  
Male And Female ◽  
Male And Female Rats

The effect of Ashwagandharishta on the lipid profile and chronic toxicity of both male and female Albino rats were observed for 51 days. Our results demonstrate that the treatment of the plant extract failed to exhibit any statistically significant change (increase/ decrease) in the serum cholesterol (Total), high density lipoprotein (HDL), low density lipoprotein (LDL) and triglyceride of the male rats. But the female rats showed highly (p<0.01) and very highly (p<0.001) significant decrease in the serum cholesterol (Total) levels of the medium and high dose treated groups respectively. Regarding HDL, ASG showed statistically significant decrease at low (p <0.05), medium (p<0.01) and high (p<0.001) dose treated female rats. The LDL level of the medium dose treated female rats were statistically significant (p <0.05). The serum Triglyceride decreased significantly at low (p<0.01) and high (p <0.05) dose treated female rats. Jahangirnagar University J. Biol. Sci. 9(1 & 2): 59-68, 2020 (June & December)

SEX DIFFERENCES IN THE CONCENTRATIONS OF GLUCOCORTICOID RECEPTORS IN RAT LIVER AND THYMUS

1979 ◽  
Vol 80 (1) ◽  
pp. 21-26 ◽  
Author(s):  
D. B. ENDRES ◽  
R. J. MILHOLLAND ◽  
F. ROSEN
Keyword(s):  
Sex Differences ◽  
Sex Difference ◽  
Glucocorticoid Receptors ◽  
Plasma Corticosterone ◽  
Female Rats ◽  
Male Rats ◽  
Ovariectomized Rats ◽  
Intact Male ◽  
Male And Female ◽  
Male And Female Rats

The effects in rats of adrenalectomy, hypophysectomy, ovariectomy or combinations of these operations on the concentrations of glucocorticoid receptors in the cytosol of liver and thymus were measured. The concentrations of glucocorticoid receptors were lower in cytosols from liver and thymus of female than of male rats. After adrenalectomy, there was a significant increase in the concentrations of receptors measured in the cytoplasm from the liver and thymus of female rats and from the liver of male rats. After adrenalectomy or hypophysectomy, there was no sex difference in the concentrations of glucocorticoid receptors in cytosols of liver or thymus. After ovariectomy, the concentration of receptors in cytosols from the thymus, but not from the liver, increased. Ovariectomized rats responded to adrenalectomy in the same way as intact male rats. The different responses shown by male and female rats to endocrine manipulation probably depend upon associated changes in plasma corticosterone concentrations which are influenced by the ovary. Differences in response between the liver and thymus probably reflect a preferential distribution of corticosterone to the liver rather than to the thymus.

Differential orderliness of the GH release process in castrate male and female rats

1998 ◽  
Vol 274 (2) ◽  
pp. R437-R444 ◽  
Author(s):  
Evelien Gevers ◽  
Steve M. Pincus ◽  
Iain C. A. F. Robinson ◽  
Johannes D. Veldhuis
Keyword(s):  
Gnrh Agonist ◽  
Rank Order ◽  
Female Rats ◽  
Sex Steroid ◽  
Intact Male ◽  
Castrate Male ◽  
Male And Female ◽  
Releasing Hormone ◽  
Male And Female Rats ◽  
The Impact

Male- and female-specific modes of episodic growth hormone (GH) release are presumptively imposed by sex steroid hormones, and, although typically evident visually, are vividly distinguished quantitatively via a regularity statistic, approximate entropy (ApEn), in both the rat and human. GH secretory patterns may determine GH-stimulated growth and specific hepatic and muscle gene expression in the rat. Consequently, it is important to discern mechanisms that underlie their regulation. Here we have examined the impact of prepubertal gonadal suppression (at 4 wk of age) via surgical or pharmacological [gonadotropin-releasing hormone (GnRH) agonist] intervention on the regularity (ApEn) of GH release in male and female rats (at 10–11 wk of age) sampled at 10-min intervals for 10 h ( n = 60 points) during a lights-out (dark) period. We observed a graded hierarchy of mean disorderliness of GH release that was quantifiable by ApEn measures, with maximal to minimal disorderliness in the following rank order: intact female, GnRH agonist-treated female, ovariectomized female, orchidectomized male, GnRH agonist-treated male, and intact male. These observations suggest a continuum of sex steroid actions on the regularity of GH secretion and, by inference, on the interplay among GH-releasing hormone, somatostatin, and GH/insulin-like growth factor I negative feedback.

SPECIFIC SUPPRESSION OF FOLLICLE-STIMULATING HORMONE SECRETION IN GONADECTOMIZED MALE AND FEMALE RATS WITH INTRASPLENIC OVARIAN TRANSPLANTS

1978 ◽  
Vol 78 (3) ◽  
pp. 399-406 ◽  
Author(s):  
J. TH. J. UILENBROEK ◽  
R. TILLER ◽  
F. H. DE JONG ◽  
F. VELS
Keyword(s):  
Hormone Secretion ◽  
Serum Levels ◽  
Female Rats ◽  
Male Rats ◽  
Vaginal Smears ◽  
Intact Male ◽  
Male And Female ◽  
Kidney Capsule ◽  
Specific Suppression ◽  
Male And Female Rats

Adult male and female rats received an ovarian homotransplant under the kidney capsule or in the spleen 14 days after gonadectomy. After transplantation under the kidney capsule, the high levels of both LH and FSH normally observed after gonadectomy decreased to the levels found in intact male and female rats. After transplantation into the spleen, however, the serum levels of LH increased still further, although a decrease was observed in the level of FSH. In male rats, the concentrations of oestradiol-17β in the plasma increased from 17 to 56 pg/ml after transplantation of an ovary under the kidney capsule; the concentration was not increased after intrasplenic ovarian transplantation. In female rats with an intrasplenic transplant, the uterine weight did not increase and vaginal smears were not cornified. Administration of oestrogen and progesterone to produce approximately the concentrations found in rats with an intrasplenic transplant did not result in decreased concentrations of FSH. These results suggest that the ovary secretes a substance with specific FSH-suppressing activity, which is not inactivated by the liver.

Growth hormone regulates the rodent hepatic epidermal growth factor receptor at a pretranslational level

1989 ◽  
Vol 3 (2) ◽  
pp. 113-120 ◽  
Author(s):  
S. Johansson ◽  
B. Husman ◽  
G. Norstedt ◽  
G. Andersson
Keyword(s):  
Epidermal Growth Factor Receptor ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Growth Factor Receptor ◽  
Female Rats ◽  
Male Rats ◽  
Intact Male ◽  
Male And Female ◽  
Male And Female Rats ◽  
Epidermal Growth

ABSTRACT Recent studies have implicated the involvement of pituitary factor(s) in the regulation of hepatic epidermal growth factor receptor (EGF-R) levels. In the present study the possible role of GH as a regulator of EGF-R has been examined by measuring hepatic EGF-R mRNA and EGF binding in intact and GH-deficient rats and mice before and after administration of GH. Using a human EGF-R probe, 10·5 and 6·0 kb transcripts were detected in mouse and rat liver by Northern gel analysis. EGF-R mRNA was quantified by solution hybridization, and EGF binding determined by incubation of 125I-labelled EGF with a low-density membrane fraction. Levels of hepatic EGF-R mRNA and binding of EGF in female rats were about two-thirds of those in male rats. GH-deficient (lit/lit) male and female mice had approximately 10 and 25% respectively of the levels of EGF-R mRNA and EGF binding of intact male and female mice. Furthermore, hypophysectomized rats exhibited a reduced level of EGF-R mRNA and EGF binding, corresponding to about 20% of the levels detected in intact male rats. When hypophysectomized male and female rats received recombinant human GH (hGH) either as intermittent injections or by continuous infusion using osmotic minipumps, the EGF-R mRNA and EGF binding levels increased to about half those of the intact male animals. No differences between intermittent or continuous administration of hGH on the induction of EGF-R mRNA or EGF binding could be seen. The correlation between mRNA and binding levels suggests regulation at a pretranslational level. There was a reduction of EGF-R mRNA to female levels when intact male rats were given hGH. An additional reduction of EGF binding levels was seen in both intact male and female rats exposed continuously to GH. This may indicate additional translational and/or post-translational regulatory mechanisms.

scholarly journals Effects of new generation triptans – frovatriptan and almotriptan – on hemodynamic parameters in intact male and female rats

2020 ◽  
Vol 70 (2) ◽  
pp. 239-247
Author(s):  
Kremena Saracheva ◽  
Petar Hrischev ◽  
Liliya Vasileva ◽  
Mariyan Topolov ◽  
Julia Nikolova ◽  
...  
Keyword(s):  
Second Generation ◽  
Female Rats ◽  
Male Rats ◽  
Hemodynamic Parameters ◽  
Intact Male ◽  
Male And Female ◽  
Arterial Blood ◽  
Male And Female Rats ◽  
Male Wistar Rats ◽  
The Impact

AbstractThe introduction of the second generation triptans in clinical and experimental practice was a major progress in the pharmacotherapy of migraine. Frovatriptan is a second generation triptan with strong 5-HT1B/1D serotonergic agonism and low 5-HT1A/7 receptor affinity, while almotriptan possesses not only the typical 5-HT1B/1D receptor agonist activity, but shows an affinity to the 5-HT1F receptor. The aim of our study was to assess the impact of frovatriptan and almotriptan on hemodynamics in male and female rats. We used a non-invasive “tail-cuff” method to measure the arterial blood pressure. Female and male Wistar rats were treated separately with high and low dosages of frovatriptan and almotriptan. Male and female rats showed reduction in all hemodynamic parameters, but only male rats showed an increase in the heart rate. In general, we could say that both almotriptan and frovatriptan potentiate cardiovascular safety.

1,2-3H-TESTOSTERONE: DISTRIBUTION AND UPTAKE IN NEURAL AND GENITAL TISSUES OF INTACT MALE, CASTRATE MALE AND FEMALE RATS

1969 ◽  
Vol 61 (4) ◽  
pp. 629-640 ◽  
Author(s):  
S. K. Roy ◽  
K. R. Laumas
Keyword(s):  
Pituitary Gland ◽  
Anterior Pituitary ◽  
Soluble Fraction ◽  
Anterior Pituitary Gland ◽  
Female Rats ◽  
Constant Infusion ◽  
Intact Male ◽  
Castrate Male ◽  
Male And Female ◽  
Male And Female Rats

ABSTRACT This report deals with a comparative study of the uptake of radioactivity in the genital, neural and other tissues of intact male, castrate male and female rats after constant infusion of radiochemically pure 1,2-3H-testosterone. Castration has been found to have a marked effect in enhancing the uptake of radioactivity in the different tissues particularly liver and kidney which have a metabolic and excretory role. Prostate and seminal vesicles, on the other hand, did not show any difference in uptake in intact and castrate rats. The uptake of testosterone and its metabolites in the prostate of intact animals was 3.46 × 10−9 m. In experiments on subcellular localization of radioactivity after constant infusion of 1,2-3H-testosterone, it was found that prostate and seminal vesicle had heavy localisation in the nuclear and 105 000 × g soluble fraction while the major localisation of radioactivity in the case of nontarget tissues like liver, intestine, muscle etc. was in the soluble fraction. Castration caused a higher uptake of radioactivity in the anterior pituitary gland, anterior and middle hypothalamus also, which could be explained on the basis of the negative feedback of the hormone. An interesting feature of the uptake of testosterone and its metabolites in the female rat was the high uptake in the anterior pituitary gland, and the various parts of the hypothalamus. These findings are discussed in light of information available on the action and feedback of sex hormones.

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