Testosterone propionate and histamine metabolism in rats

1961 ◽  
Vol 201 (4) ◽  
pp. 740-742 ◽  
Author(s):  
K. S. Kim
Keyword(s):  
Testosterone Propionate ◽  
Subcutaneous Administration ◽  
Repeated Administration ◽  
Female Rats ◽  
Male Rats ◽  
Ovariectomized Rats ◽  
Sprague Dawley ◽  
Histamine Metabolism ◽  
Experimental Conditions ◽  
Close Relationship

Urinary histamine output has been studied under various experimental conditions in rats. Orchidectomy increased the output of free histamine in rats of the Sprague-Dawley strain but not in rats of the Wistar strain. Subcutaneous administration of testosterone propionate (1 mg/rat) suppressed the output of free histamine in ovariectomized rats but not in normal females, which showed the effect only after repeated administration of this hormone. When exogenous histamine (100 µg) was administered at a constant rate over a 4-hr period, only a minute quantity of administered histamine appeared as free histamine in the urine of male rats. In contrast, 23% of administered histamine appeared as free histamine in the urine of female rats. When repeatedly treated with testosterone, female rats eliminated exogenous histamine more like males. The close relationship between testosterone and histamine metabolism in rats is thus clearly demonstrated.

Estrogen enhances baroreflex control of heart rate in conscious ovariectomized rats

1998 ◽  
Vol 76 (4) ◽  
pp. 381-386 ◽  
Author(s):  
Mahmoud M El-Mas ◽  
Abdel A Abdel-Rahman
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Baroreflex Sensitivity ◽  
Female Rats ◽  
Male Rats ◽  
Ovariectomized Rats ◽  
Sprague Dawley ◽  
Baroreflex Control ◽  
Baroreflex Function ◽  
Vehicle Treatment

In previous studies, we have shown that the baroreflex control of heart rate is significantly attenuated in females compared with age-matched males. This study investigated the role of estrogen in the modulation of baroreflex function in conscious unrestrained rats. Baroreflex-mediated decreases in heart rate in response to increments in blood pressure evoked by phenylephrine were evaluated in conscious freely moving male and female Sprague-Dawley rats as well as in ovariectomized rats. The effect of a 2-day 17 beta -estradiol (50 µg ·kg-1 ·day-1, s.c.) or vehicle treatment on baroreflex sensitivity was investigated in ovariectomized rats. Intravenous bolus doses of phenylephrine (1-16 µg/kg) elicited dose-dependent pressor and bradycardic responses in all groups of rats. Regression analysis of the baroreflex curves relating increments in blood pressure to the associated heart rate responses revealed a significantly (p < 0.05) smaller baroreflex sensitivity in female compared with male rats (-1.22 ± 0.07 and -1.85 ± 0.15 beats ·min-1 ·mmHg-1, respectively), suggesting an attenuated baroreflex function in females. In age-matched ovariectomized rats, baroreflex sensitivity showed further reduction (-0.93 ± 0.02 beats ·min-1 ·mmHg-1). Treatment of ovariectomized rats with 17 beta -estradiol significantly (p < 0.05) enhanced the baroreflex sensitivity (-1.41 ± 0.16 beats ·min-1 ·mmHg-1) to a level that was slightly higher than that of sham-operated female rats. Furthermore, baroreflex sensitivity of ovariectomized estradiol-treated rats was not significantly different from that of age-matched male rats. The vehicle, on the other hand, had no effect on baroreflex sensitivity of ovariectomized rats. These data support our earlier findings that sexual dimorphism exists in baroreflex control of heart rate. More importantly, the present study provides experimental evidence that suggests a facilitatory role for estrogen in the modulation of baroreflex function.Key words: rat, gender, baroreflex sensitivity, 17 beta -estradiol, ovariectomy.

SEXUAL DIFFERENCE IN THE EFFECT OF CYPROTERONE ACETATE AND GLUCOCORTICOIDS ON α2u-GLOBULIN IN GONADECTOMIZED RATS

1978 ◽  
Vol 79 (1) ◽  
pp. 135-136 ◽  
Author(s):  
G. VANDOREN ◽  
W. HEYNS ◽  
G. VERHOEVEN ◽  
P. DE MOOR
Keyword(s):  
Cyproterone Acetate ◽  
Sexual Difference ◽  
Testosterone Propionate ◽  
Female Rats ◽  
Male Rats ◽  
Ovariectomized Rats ◽  
Major Protein ◽  
Intact Male ◽  
Male And Female Rats ◽  
Pituitary Glands

Laboratorium voor Experiméntele Geneeskunde, Katholieke Universiteit Leuven, Rega Instituut, Minderbroedersstraat 10, B-3000 Leuven, Belgium (Received 28 March 1978) The synthesis of α2u-globulin, the major protein found in the urine of adult male rats (Roy & Neuhaus, 1966; Roy, Neuhaus & Harmison, 1966), is controlled by several hormones. Androgens, growth hormone, thyroxine and glucocorticoids promote the synthesis of this protein, whereas oestrogens and a factor secreted by ectopically transplanted pituitary glands suppress it (Roy & Neuhaus, 1967; Roy, 1973; Kurtz, Sippel & Feigelson, 1976; Vandoren, Van Baelen, Verhoeven & De Moor, 1978). Cyproterone acetate (CA), a potent antiandrogen, inhibits the androgenic induction of α2u-globulin in ovariectomized rats, but does not suppress its synthesis in intact male rats (Roy, 1976). In the present experiments, the influence of CA on the induction of α2u-globulin by testosterone propionate (TP) in the serum of gonadectomized male and female rats was compared. Evidence is presented for

CIRCADIAN RHYTHM OF PROLACTIN SURGES INDUCED BY STIMULATION OF THE UTERINE CERVIX IN THE OVARIECTOMIZED RAT: ITS SEXUAL DIFFERENTIATION AND PREOPTIC REGULATION

1981 ◽  
Vol 91 (2) ◽  
pp. 325-334 ◽  
Author(s):  
MASAZUMI KAWAKAMI ◽  
JUN ARITA
Keyword(s):  
Circadian Rhythm ◽  
Uterine Cervix ◽  
Testosterone Propionate ◽  
Neonatal Period ◽  
Female Rats ◽  
Male Rats ◽  
Ovariectomized Rats ◽  
Optic Chiasma ◽  
Bilateral Lesions ◽  
Stimulation Of

Stimulation of the uterine cervix (CS) induced a nocturnal surge of prolactin at 04.00 h and a diurnal surge at 17.00 h in normal ovariectomized rats. However, the CS-induced prolactin surges did not occur in ovariectomized rats which had been treated with 250 μg testosterone propionate during the neonatal period. Chronic bilateral lesions of the suprachiasmatic nucleus (SCN) completely abolished the CS-induced nocturnal and diurnal surges of prolactin release which were observed in sham-lesioned, ovariectomized rats. Furthermore, bilateral lesions of the medial basal part of the suprachiasmatic area (MBSC), lying rostral to the SCN, were also effective in blocking the CS-induced nocturnal and diurnal surges. Lesions which destroyed mainly the optic chiasma and extended partially into the MBSC and SCN did not block the CS-induced prolactin surges. These results suggest that one reason for the failure of ovary-grafted male rats and neonatally androgenized female rats to maintain pseudopregnancy is the extinction of the circadian rhythm of the two daily prolactin surges, and that the MBSC, in addition to the SCN which is known to be a generator of other circadian rhythms, is involved in generation of the rhythm of prolactin surges.

The role of sex steroids in the formation of sex-differentiated concentrations of corticosteroid-binding globulin in rats

1992 ◽  
Vol 132 (2) ◽  
pp. 235-240 ◽  
Author(s):  
G. D. Mataradze ◽  
R. M. Kurabekova ◽  
V. B. Rozen
Keyword(s):  
Sex Steroids ◽  
Testosterone Propionate ◽  
Mature Female ◽  
Female Rats ◽  
Male Rats ◽  
Ovariectomized Rats ◽  
Adult Males ◽  
Short Period ◽  
Corticosteroid Binding Globulin

ABSTRACT The role of sex steroids in the programming of the level of serum corticosteroid-binding globulin (CBG) in the rat has been studied at different stages of ontogenesis. The CBG content in the serum of mature female rats was 2·5 times higher than that in male rats. Sexual dimorphism of CBG content was absent in immature animals of 3–4 weeks of age. Castration of mature rats led to a 40–50% increase in CBG content. The CBG concentration in mature females or castrated adult males treated with testosterone propionate (TP; 3 mg/day for 4 days) was decreased by 40–50% compared with vehicle-treated rats. Oestradiol injection (1 μg/day for 4 days) had no influence on CBG levels in mature male and ovariectomized adult female rats. Immature rats were castrated on days 1, 7, 14, 21, 28 or 35 of age and the CBG level was determined at 10–12 weeks of age. The CBG content of rats castrated up to day 28 of age was 2·5 times higher than that in mature males and did not differ from that in mature females. The CBG content of male rats castrated on day 35 of age was the same as that of adult castrated males. The CBG level in castrated rats treated with TP (1·25 mg for days 1–3 or 300 μg/day for 5 days after castration at day 7 up to day 26) did not differ from that in controls (i.e. vehicle-treated rats). TP injection into castrated rats on days 29–33 of age (300 μg/day) led to a 40–50% decrease in CBG level when compared with controls. Ovariectomy of rats at different ages (on days 1 or 28 or 3 months) did not affect CBG concentration. TP injection (300 μg/day) into ovariectomized rats on days 29–33 had the same effect on CBG concentration as in males. Gonadectomized rats treated with diethylstilboestrol on days 29–33 (100 μg/day) had the same CBG concentrations as TP-treated rats. It was concluded that there is a short period during ontogenesis, from days 29 to 35 of age, which is critical for irreversible masculinization of the CBG concentration in male rats. Journal of Endocrinology (1992) 132, 235–240

Effects of Guanethidine and Related Compounds on Histamine Excretion

1972 ◽  
Vol 50 (6) ◽  
pp. 539-544 ◽  
Author(s):  
J. LeBlanc ◽  
J. Côté ◽  
F. Doré ◽  
S. Rousseau
Keyword(s):  
Peritoneal Fluid ◽  
Fold Increase ◽  
Female Rats ◽  
Male Rats ◽  
Daily Injection ◽  
Histamine Metabolism ◽  
Methyl Transferase ◽  
Single Intraperitoneal Injection ◽  
Urinary Histamine ◽  
Related Compounds

The basic nature of guanethidine and some of its effects suggested a possible action of this drug on histamine metabolism. A single intraperitoneal injection of guanethidine (10 mg/kg) in male rats was found to double the daily urinary excretion of free histamine; daily injection for three weeks caused a 10-fold increase. In male rats, guanethidine increased the number of mast cells in the peritoneal fluid and, in both peritoneal fluid and mesentery, caused a significant degranulation of these cells; this action was not observed in female rats. This finding may indicate that guanethidine blocks methylation of histamine by inhibiting imidazole methyl transferase since this enzyme is found in male but not in female rats. Bethanidine and reserpine had no effect on histamine excretion. Imidazole was found to be even more potent than guanethidine in causing an increase in urinary histamine. Guanethidine and imidazole neither potentiated nor mimicked the action of histamine on the isolated ileum.

OESTROGEN RESPONSES OF RATS NEONATALLY STERILIZED WITH STEROIDS

1969 ◽  
Vol 45 (3) ◽  
pp. 415-420 ◽  
Author(s):  
T. R. WRENN ◽  
JOAN R. WOOD ◽  
J. BITMAN
Keyword(s):  
Testosterone Propionate ◽  
Female Rats ◽  
Ovariectomized Rats ◽  
Uterine Weight ◽  
Oestradiol Benzoate

SUMMARY At 75 days of age, female rats neonatally sterilized with oestradiol benzoate or testosterone propionate were compared with normal and ovariectomized rats with regard to their 6-hr. response to 0·2 μg. oestradiol 17β. The greatest increases in uterine weight, glucose and glycogen concentrations and per cent uterine water occurred in the ovariectomized animals. A marked oestrogen response also occurred in the animals neonatally sterilized with oestradiol benzoate. The response of the normal rats was slight, and the testosterone propionate-treated rats were the least affected. Adrenal, pituitary, and ovarian weights were found to be affected by the neonatal hormone treatments. Vaginal patency was completely inhibited in the rats injected with testosterone propionate. It is concluded that rats neonatally sterilized with steroids are much less suitable than ovariectomized animals for oestrogen assays.

scholarly journals Different mechanisms of regulation of nuclear reduced nicotinamide–adenine dinucleotide phosphate-dependent 3-oxo steroid 5α-reductase activity in rat liver, kidney and prostate

1974 ◽  
Vol 142 (2) ◽  
pp. 273-277 ◽  
Author(s):  
Jan-Åke Gustafsson ◽  
Åke Pousette
Keyword(s):  
Testosterone Propionate ◽  
Reductase Activity ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Female Rats ◽  
Male Rats ◽  
Regulatory Mechanisms ◽  
Oestradiol Benzoate ◽  
Liver And Kidney ◽  
Reduced Nicotinamide Adenine Dinucleotide ◽  
Hydroxy Steroid

The regulatory mechanisms involved in the control of the nuclear NADPH-dependent 3-ketosteroid 5α-reductase (5α-reductase) activity were studied in liver, kidney and prostate. The substrate used was [1,2-3H]androst-4-ene-3,17-dione (androstenedione) (for liver and kidney) or [4-14C]androstenedione (for prostate). The hepatic nuclear 5α-reductase activity was greater in female than in male rats, was greater in adult than in prepubertal female rats, increased after castration of male rats, but was not affected by treatment with testosterone propionate or oestradiol benzoate. These regulatory characteristics are in part different from those previously described for the hepatic microsomal 5α-reductase. The renal nuclear metabolism of androstenedione, i.e. 5α reduction and 17β-hydroxy steroid reduction, was relatively unaffected by sex, age, castration and treatment with testosterone propionate. However, treatment of castrated male rats with oestradiol benzoate led to a significant increase in the 5α-reductase activity and a significant decrease in the 17β-hydroxy steroid reductase activity. Finally, the nuclear 5α-reductase activity in prostate was androgen-dependent, decreasing after castration and increasing after treatment with testosterone propionate. In conclusion, the nuclear 5α-reductase activities in liver, kidney and prostate seem to be under the control of distinctly different regulatory mechanisms. The hypothesis is presented that whereas the prostatic nuclear 5α-reductase participates in the formation of a physiologically active androgen, 5α-dihydrotestosterone, this may not be the true function of the nuclear 5α-reductase in liver and kidney. These enzymes might rather serve to protect the androgen target sites in the chromatin from active androgens (e.g. testosterone) by transforming them into less active androgens (e.g. 5α-androstane-3,17-dione and/or 5α-dihydrotestosterone).

Abstract P045: Sex And Age Specific Circulating Aldosterone Changes In Transgenic Hypertensive (mRen2)27 Rats And Hannover Sprague Dawley (SD) Rats And Its Association With Blood Pressure And Cardiac Function

Hypertension ◽  
2020 ◽  
Vol 76 (Suppl_1) ◽  
Author(s):  
Fatima Ryalat ◽  
N Cruz-Diaz ◽  
W Graham ◽  
T Gwathmey-Williams ◽  
P E Gallagher ◽  
...  
Keyword(s):  
Heart Failure ◽  
Blood Pressure ◽  
Cardiac Function ◽  
Target Organ Damage ◽  
Aging Effect ◽  
Female Rats ◽  
Male Rats ◽  
Sprague Dawley ◽  
Aldosterone Antagonists ◽  
Sd Rats

Aldosterone plays a significant role in hypertension and target organ damage. Aldosterone antagonists are used in the management of heart failure. However, neither the influence of age nor sex on aldosterone pathophysiology is well understood. We investigated the changes in circulating aldosterone with age and its association with cardiovascular function, using male and female hypertensive renin transgenic (mRen2)27 rats and SD rats at 20 and 50 weeks of age. Both male (22 ± 3 vs. 12 ± 2 ng/dL, n = 9 - 12, p < 0.05) and female (59 ± 10 vs. 23 ± 8 ng/dL, n = 6 - 10, p < 0.05) hypertensive rats had higher serum aldosterone compared with SD rats at 20 weeks of age. At 50 weeks of age, the difference persisted in the hypertensive female rats (63 ± 8 vs. SD: 33 ± 7 ng/dL, n = 6 - 7, p < 0.05), but not in the males. SD male rats have higher systolic blood pressure (SBP) as they age, and consequently develop cardiac diastolic dysfunction associated with higher aldosterone at 50 weeks compared to 20 weeks (28 ± 3 vs. 12 ± 2 ng/dL, n = 7 - 9, p < 0.05). This aging effect on aldosterone was not significant in the other groups. We showed previously that SD males treated with polyphenol rich muscadine grape extract (MGE) have lower aldosterone, less aortic stiffness and better cardiac diastolic function (E/e’) than controls at the older age; the MGE effect was not seen in (mRen2)27 males. Sex differences in aldosterone were not significant in the SD rats at either time point. However, (mRen2)27 female rats had higher aldosterone than (mRen2)27 males at both 20 weeks (59 ± 10 vs. 22 ± 3 ng/dL, n = 10 - 12, p < 0.05) and 50 weeks (63 ± 8 vs. 31 ± 7 ng/dL, n = 6 - 7, p < 0.05), despite the lack of significant differences in SBP. (mRen2)27 female rats preserve cardiac function better than males throughout their life span, while males develop indices of heart failure. Our data suggest that lower aldosterone levels in hypertensive males compared with females do not protect against the higher lifetime burden of elevated SBP and also may reflect different mechanisms controlling circulating aldosterone between sexes. In addition, data suggest a potential therapeutic effect of MGE in the management of age-associated moderate hypertension.

EFFECTS OF TESTOSTERONE MEDIATED OR MODULATED BY PITUITARY FACTORS

1975 ◽  
Vol 67 (1) ◽  
pp. 71-79 ◽  
Author(s):  
P. DE MOOR ◽  
M. ADAM-HEYLEN ◽  
H. VAN BAELEN ◽  
G. VERHOEVEN
Keyword(s):  
Body Weight ◽  
Testosterone Propionate ◽  
Total Body Weight ◽  
Seminal Vesicles ◽  
Female Rats ◽  
Male Rats ◽  
Intact Male ◽  
Adult Rats ◽  
Organ Weights ◽  
Total Body

SUMMARY Adult rats of both sexes were either gonadectomized or hypophysectomized and gonadectomized. Three to eight weeks later they were treated for 14 consecutive days with oil or with 75 or 200 μg testosterone propionate (TP) per 100 g body weight. The animals were killed and for each sex the gonadectomized animals were compared with the hypophysectomized-gonadectomized animals as far as their NADPH- and NADH-dependent 3α-hydroxysteroid dehydrogenases (3α-HSD) in renal microsomes, transcortin levels in serum and five organ weights relative to total body weight were concerned. For two of the latter, i.e. the relative kidney and prostatic weights, no significant differences were found. Transcortin levels, relative adrenal weights and renal NADPH-dependent 3α-HSD activities were higher in oil-treated gonadectomized animals than in oil-treated hypophysectomized-gonadectomized animals. The opposite was found for the relative weights of uterus and seminal vesicles and renal NADH-dependent 3α-HSD activities. These differences between gonadectomized and hypophysectomized-gonadectomized animals disappeared after TP treatment as far as transcortin levels were concerned but remained for the five other parameters. After gonadectomy sexual differences subsisted for all parameters studied. But whereas intact male rats had higher NADH-dependent 3α-HSD activities than female rats the opposite was found after gonadectomy. After gonadectomy plus hypophysectomy the between sex differences disappeared as far as transcortin levels were concerned but remained in the other parameters studied.

Sexual dimorphism in vasopressin-induced contraction of rat aorta

1991 ◽  
Vol 260 (2) ◽  
pp. H453-H458 ◽  
Author(s):  
J. N. Stallone ◽  
J. T. Crofton ◽  
L. Share
Keyword(s):  
Estrous Cycle ◽  
Vascular Reactivity ◽  
Rat Aorta ◽  
Isometric Tension ◽  
Female Rats ◽  
Male Rats ◽  
Maximal Response ◽  
Sprague Dawley ◽  
Tension Development ◽  
Sprague Dawley Rats

Previously, we reported that, in the rat, pressor responsiveness to vasopressin (VP) is higher in males than in females during most phases of the estrous cycle. To explore the role of the vasculature in this phenomenon, we examined vascular reactivity to VP in thoracic aortas of male rats and female rats during each phase of the estrous cycle. Aortic rings were prepared from age-matched male and female Sprague-Dawley rats and mounted for isometric tension recording. Maximal response of female aortas to VP (4,246 +/- 163 mg/mg ring dry wt) was more than twice (P less than 0.001) that of male aortas (1,877 +/- 215 mg/mg ring wt). Sensitivity of female aortas to VP was substantially higher (P less than 0.001) than that of male aortas (EC50: 10.9 +/- 0.7 vs. 19.0 +/- 1.6 nM, respectively). Maximal rate of tension development (dT/dtmax) during contraction with VP was nearly twofold higher (P less than 0.01) in female aortas (536 +/- 23 mg/min) than in male aortas (300 +/- 19 mg/min). Maximal response, sensitivity, and dT/dtmax of female aortas did not vary significantly during the estrous cycle. Maximal response of female aortas to phenylephrine (PE; 1,251 +/- 93 mg/mg ring wt) was half that (P less than 0.001) of male aortas (2,546 +/- 194 mg/mg ring wt); sensitivity to PE did not differ significantly (EC50: 0.33 +/- 0.02 vs. 0.38 +/- 0.06 microM, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

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