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.

FACTORS INFLUENCING THE EXCRETION OF A FAT-MOBILIZING SUBSTANCE IN THE URINE OF RATS

1966 ◽  
Vol 44 (1) ◽  
pp. 95-101 ◽  
Author(s):  
J. R. Beaton ◽  
A. J. Szlavko ◽  
J. A. F. Stevenson
Keyword(s):  
Body Weight ◽  
Sex Difference ◽  
Specific Activity ◽  
Young Male ◽  
Total Activity ◽  
Female Rats ◽  
Male Rats ◽  
Diabetic Rat ◽  
Adult Rats ◽  
Factors Influencing

The effect of various factors on excretion of a lipid-mobilizing activity in FMS IA (anorexigenic) and in FMS IB (fat-mobilizing) by the fasting rat has been investigated. During fasting, the greatest excretion of such activity in FMS IA and FMS IB occurred in the first 24 hours and diminished thereafter up to 72 hours; and the specific activity of FMS IB was greatest in the first 24 hours whereas that of FMS IA was constant throughout. The hypothalamicobese rat excretes FMS IA and FMS IB in greater than normal amounts. The alloxan-diabetic rat excretes less total activity of FMS IA and IB than do control animals. Young male rats excrete greater amounts of FMS IB, but not of FMS IA, than do adult rats, the greatest excretion per 100 g body weight being observed at approximately 37 days of age. At 27 days of age (prepuberty), male rats excreted a greater total activity of FMS IB but not of FMS IA than did female rats. At 90 days of age (post-puberty), there was no apparent sex difference in the amount of total activity of FMS IB excreted per rat, but when expressed per 100 g body weight, females excreted more FMS IB than did males.

Effect of the anterior pituitary gland and gonads on enzyme components of the hepatic microsomal cytochrome P-450 system of male and female rats

1983 ◽  
Vol 96 (2) ◽  
pp. 259-267 ◽  
Author(s):  
B. Gillham ◽  
J. S. M. Hutchinson ◽  
M. B. Thorn
Keyword(s):  
Sex Difference ◽  
Anterior Pituitary ◽  
Testosterone Propionate ◽  
Specific Activity ◽  
Female Rats ◽  
Intact Male ◽  
Adult Rats ◽  
Microsomal Cytochrome ◽  
Male And Female Rats ◽  
Cytochrome P 450

The concentration of cytochrome P-450 in microsomes prepared from the livers of mature female Wistar-derived rats was significantly lower than in mature males. This sex difference was abolished after hypophysectomy, when the concentration of the cytochrome in males and females was not significantly different from that in the intact male. A concentration of cytochrome P-450 characteristic of females was restored by two anterior pituitary transplants under the kidney capsule of hypophysectomized females; a partial 'feminization' occurred in similarly treated hypophysectomized males. A partial 'feminization' was also achieved by the administration of rat or sheep prolactin to hypophysectomized females. Unexpectedly, the administration of l-dihydroxyphenylalanine to normal females was without effect on cytochrome P-450, whereas in intact males 'feminization' resulted. Castration of adult rats resulted in the 'feminization' of cytochrome P-450, whereas ovariectomy was without effect. Administration of testosterone propionate for 10 days, either immediately after the operation or 14 weeks later to rats castrated when adult failed, however, to reverse the fall in cytochrome P-450. The establishment of a higher concentration of cytochrome P-450 in the liver of female rats could not be brought about by the administration of testosterone propionate, whether given as a single dose on the second day after birth or as a 10-day course of treatment after puberty or both. It is concluded that the sex difference in hepatic microsomal cytochrome P-450 is maintained by the release in the female of an anterior pituitary factor(s) that serves to depress its concentration. The factor(s) shows some of the characteristics of prolactin but the findings are not consistent with that hormone being responsible for all of the effects observed. The release of the factor(s) in the male may be inhibited by a compound of gonadal origin other than testosterone. A sex difference could not be 'imprinted' in the female by either neonatal and/or postpubertal testosterone treatment. The concentration of hepatic microsomal cytochrome b5 and the specific activity of NADPH-cytochrome c reductase were found not to be sex-dependent in the rats used. However, anterior pituitary factor(s) other than prolactin and growth hormone act to suppress partially the concentration of the former and to promote the specific activity of the latter in the endoplasmic reticulum of rat hepatocytes.

scholarly journals MICROBODIES IN EXPERIMENTALLY ALTERED CELLS

1969 ◽  
Vol 40 (3) ◽  
pp. 734-746 ◽  
Author(s):  
Donald Svoboda ◽  
Daniel Azarnoff ◽  
Janardan Reddy
Keyword(s):  
Catalase Activity ◽  
Estradiol Benzoate ◽  
Significant Degree ◽  
Female Rats ◽  
Male Rats ◽  
Rapid Decline ◽  
Hypolipidemic Effect ◽  
Intact Male ◽  
Adult Rats ◽  
Sufficient Cause

The liver cells of intact male rats given ethyl-α-p-chlorophenoxyisobutyrate (CPIB) characteristically show a marked increase in microbodies and in catalase activity, while those of intact female rats do not. In castrated males given estradiol benzoate and CPIB the increase in catalase activity and microbody proliferation is abolished, while in castrated females given testosterone propionate and CPIB the livers show a marked increase in microbodies and in catalase activity. No sex difference in microbody and catalase response is apparent in fetal and neonatal rats. Both sexes show a sharp rise in catalase activity on the day of birth, with a rapid decline at 5 days after birth. Thyroidectomy abolishes the hypolipidemic effect of CPIB in rats, but microbody proliferation and increase in catalase activity persists in thyroidectomized male rats, indicating that microbody proliferation can be independent of hypolipidemia. Adrenalectomy does not alter appreciably the microbody-catalase response to CPIB. These experiments demonstrate that (1) in adult rats, hepatic microbody proliferation is dependent to a significant degree upon male sex hormone but is largely independent of thyroid or adrenal gland hormones; (2) hepatic microbody proliferation is independent of the hypolipidemic effect of CPIB; (3) displacement of thyroxine from serum protein may not be sufficient cause for stimulation of microbody formation.

Oral (Drinking Water) Two-Generation Reproductive Toxicity Study of Dibromoacetic Acid (DBA) in Rats

2002 ◽  
Vol 21 (4) ◽  
pp. 237-276 ◽  
Author(s):  
M. S. Christian ◽  
R. G. York ◽  
A. M. Hoberman ◽  
J. Frazee ◽  
L. C. Fisher ◽  
...  
Keyword(s):  
Drinking Water ◽  
Body Weight ◽  
Female Rats ◽  
Male Rats ◽  
Feed Consumption ◽  
Organ Weights ◽  
Body Weights ◽  
Group Generation ◽  
Generation Male ◽  
F1 Generation

In a two-generation study of dibromoacetic acid (DBA), Crl SD rats (30 rats/sex/group/generation) were provided DBA in drinking water at 0 (reverse osmosis-deionized water), 50,250, and 650 ppm (0,4.4 to 11.6,22.4 to 55.6, and 52.4 to 132.0 mg/kg/day, respectively; human intake approximates 0.1 μg/kg/day [0.0001 mg/kg/day]). Observations included viability, clinical signs, water and feed consumption, body and organ weights, histopathology, and reproductive parameters (mating, fertility, abortions, premature deliveries, durations of gestation, litter sizes, sex ratios and viabilities, maternal behaviors, reproductive organ weights, sperm parameters and implantation sites, sexual maturation). Histopathological evaluations were performed on at least 10 P and F1 rats/sex at 0 and 650 ppm (gross lesions, testes, intact epididymis; 10 F1 dams at 0, 250, and 650 ppm for primordial follicles). Developmental observations included implantations, pup numbers, sexes, viabilities, body weights, morphology, and reproductive performance. At 50 ppm and higher, both sexes and generations had increased absolute and relative liver and kidneys weights, and female rats in both generations had reduced absolute and relative adrenal weights; adrenal changes were probably associated with physiological changes in water balance. The livers and kidneys (10/sex/group/generation) had no histopathological changes. Other minimal effects at 50 ppm were reduced water consumption and a transient reduction in body weight. At 250 and 650 ppm, DBA reduced parental water consumption, body weight gains, body weights, feed consumption, and pup body weights. P and F1 generation male rats at 250 and 650 ppm had altered sperm production (retained step 19 spermatids in stages IX and X tubules sometimes associated with residual bodies) and some epididymal tubule changes (increased amounts of exfoliated spermatogenic cells/residual bodies in epididymal tubules, atrophy, and hypospermia), although inconsistently and at much lower incidences. Unilateral abnormalities of the epididymis (small or absent epididymis) at 650 ppm in four F1 generation male rats were considered reproductive tract malformations. The no-observable-adverse-effect level (NOAEL) and reproductive and developmental NOAELs for DBA were at least 50 ppm (4.5 to 11.6 mg/kg/day), 45,000 to 116,000 times the human adult exposure level. Reproductive and developmental effects did not occur in female rats exposed to DBA concentrations as high as 650 ppm. Based on the high multiples of human exposure required to produce effects in male rats, DBA should not be identified as a human reproductive or developmental risk.

Hyperprolactinaemia attenuates the gonadotrophin releasing hormone receptor response to gonadectomy in rats

1982 ◽  
Vol 95 (2) ◽  
pp. 267-274 ◽  
Author(s):  
R. N. Clayton ◽  
L. C. Bailey
Keyword(s):  
Female Rats ◽  
Male Rats ◽  
Serum Prolactin ◽  
Intact Male ◽  
Adult Rats ◽  
Releasing Hormone ◽  
Receptor Response ◽  
Serum Lh ◽  
Gonadotrophin Releasing Hormone ◽  
Qualitative Index

Measurement of pituitary gonadotrophin releasing hormone (Gn-RH) receptor content provides a qualitative index of prior exposure of the pituitary gland to endogenous Gn-RH. The effect of moderate hyperprolactinaemia (serum prolactin = 95–250 μg/l), achieved with three pituitary grafts beneath the renal capsule, on the pituitary Gn-RH receptor content and serum LH responses to gonadectomy of adult rats has been studied. In males the presence of hyperprolactinaemia for 7 days completely prevented the increase in Gn-RH receptor content 3 days after castration and inhibited the serum LH rise by 45%. By 6 days after castration, Gn-RH receptors had increased in the hyperprolactinaemic castrated animals but values were 33% lower than in sham-grafted controls, while the serum LH increase was attenuated by 30%. Pituitary LH content was also lower in grafted castrated animals 6 days after castration. Hyperprolactinaemia for 3 weeks had no effect on Gn-RH receptors or pituitary LH content of intact male rats, although basal serum LH was decreased by 50%. Hyperprolactinaemia also attenuated the increases in Gn-RH receptors, serum LH and pituitary LH which occurred 6 days after ovariectomy in female rats. In all experiments the pituitary content of prolactin was reduced by 80–90% in animals bearing pituitary grafts. These results suggest that hyperprolactinaemia restricts the Gn-RH receptor response to gonadectomy by decreasing endogenous hypothalamic Gn-RH secretion.

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.

STUDIES ON THE EFFECT OF HORMONE ADMINISTRATION ON BODY WEIGHT AND ON TIBIAL EPIPHYSIAL CARTILAGE WIDTH IN INTACT, HYPOPHYSECTOMIZED AND ADRENALECTOMIZED RATS

1963 ◽  
Vol 25 (4) ◽  
pp. 473-482 ◽  
Author(s):  
HELEN E. C. CARGILL THOMPSON ◽  
G. P. CREAN
Keyword(s):  
Growth Hormone ◽  
Body Weight ◽  
Young Male ◽  
Total Body Weight ◽  
Male Rats ◽  
Unilateral Nephrectomy ◽  
Hormone Administration ◽  
Epiphysial Cartilage ◽  
Hypophysectomized Rats ◽  
Total Body

SUMMARY 1. The effects of feeding, hormone administration, unilateral nephrectomy and adrenalectomy on width of tibial cartilage and total body weight in intact and hypophysectomized young male rats were measured. 2. Unilateral nephrectomy and adrenalectomy have no effect on the cartilage width of both intact and hypophysectomized rats, although adrenalectomy causes a loss in weight in the intact rat. 3. Intact rats, both young and adult, fed enough to maintain but not to put on weight, show a reduction of cartilage width to hypophysectomized levels. 4. Growth hormone alone (1 mg. and 3 mg./day for 14 days) causes a marked increase in cartilage width but only a 50–60% increase in total body weight in the hypophysectomized rat. 5. Adrenocorticotrophin (ACTH: 2 i.u./day for 14 days) causes a significant reduction in both cartilage width and total body weight in the hypophysectomized rat. 6. Thyrotrophin (TSH: 1 i.u./day) and Prolactin (1 mg. and 2 mg./day) caused significant increases in both total body weight and cartilage width in the hypophysectomized rat. 7. Luteinizing hormone (LH: 0·01 mg./day) together with follicle stimulating hormone (FSH: 1·0 mg./day) caused a significant increase in body weight, but had no effect on cartilage width in the hypophysectomized rat. 8. Both doses of combined hormones (growth hormone, ACTH, TSH, prolactin, FSH and LH administered together) caused a marked increase in cartilage width and a smaller increase in total body weight in the hypophysectomized rat.

scholarly journals Regulation of serum leptin levels by gonadal function in rats

1999 ◽  
pp. 468-473 ◽  
Author(s):  
L Pinilla ◽  
LM Seoane ◽  
L Gonzalez ◽  
E Carro ◽  
E Aguilar ◽  
...  
Keyword(s):  
Body Weight ◽  
Estrous Cycle ◽  
Female Rats ◽  
Male Rats ◽  
Ovariectomized Rats ◽  
Internal Diameter ◽  
External Diameter ◽  
Gonadal Function ◽  
Intact Male ◽  
Serum Leptin

The aim of this study was to investigate the regulation of serum leptin levels by gender and gonadal steroid milieu. Thus, we measured serum leptin levels by radioimmunoassay in (a) intact male and female rats, (b) female rats at different stages of the estrous cycle and (c) ovariectomized or orchidectomized rats. Gonadectomized groups were or were not implanted with silastic capsules (10 or 30 mm in length, 1.519mm internal diameter; 3.06 mm external diameter) containing estradiol or testosterone and decapitated two weeks later. We found (i) intact female rats weighing 50 g, 250 g and 300 g exhibited higher serum leptin concentrations than intact male rats of similar body weight; (ii) leptin concentrations were not affected by the phase of the estrous cycle; (iii) two weeks after gonadectomy serum leptin concentrations increased in both male (from 4.47+/-1.87 to 8.76+/-1.24 ng/ml) and female (from 1.97+/-0.46 to 5.29+/-0.51 ng/ml) rats. The ovariectomy-induced increase in serum leptin levels was not dependent, at least completely, on changes in body weight since it could be observed when comparisons were made between ovariectomized rats and intact rats in estrus matched for body weight. In contrast the effect of orchidectomy on serum leptin levels appears to be dependent on changes in body weight since it was no longer observed when comparisons were made with a group of intact male rats matched for body weight. In conclusion, these results suggest that serum leptin concentrations are controlled by gonadal function either directly or as a consequence of changes in body weight.

LORDOSIS BEHAVIOUR IN MALE, FEMALE AND ANDROGENIZED FEMALE RATS

1976 ◽  
Vol 70 (3) ◽  
pp. 409-420 ◽  
Author(s):  
P. SÖDERSTEN
Keyword(s):  
Testosterone Propionate ◽  
Female Rats ◽  
Male Rats ◽  
High Dose ◽  
Normal Female ◽  
Adult Rats ◽  
Oestradiol Benzoate ◽  
Series Of Experiments ◽  
Lordosis Behaviour ◽  
Dose Dependent

SUMMARY Sex differences in the lordosis response of adult rats to ovarian hormones were studied in a series of experiments. Male rats were less sensitive to oestradiol benzoate (OB, a single injection of 10, 100 or 1000 μg/kg or seven daily injections of 2, 10 or 50 μg/kg) than were female rats. Oestradiol benzoate-primed (10 μg/kg) female, but not male, rats showed dose-dependent responses to progesterone (0·4, 2·0 or 10·0 mg/kg). Male rats responded clearly to progesterone (2 mg/rat) only when primed with a high dose of OB (100 μg/rat). Display of the whole pattern of female sexual behaviour was induced in male rats by treatment with 100 μg OB and 2 mg progesterone. Female rats treated with 1 mg testosterone propionate (TP) on day 4 of life, ovariectomized as adults and tested under the same endocrine conditions as the rats described above, retained behavioural OB sensitivity but responded poorly to progesterone. Evidence is presented that ovarian secretions during development significantly modify the response of neonatally TP-treated and normal female rats to OB in adulthood.

Paradoxical organ-specific adaptations to streptozotocin diabetes mellitus in adult rats

1988 ◽  
Vol 254 (6) ◽  
pp. E749-E755
Author(s):  
D. J. Pillion ◽  
R. L. Jenkins ◽  
J. A. Atchison ◽  
C. R. Stockard ◽  
R. S. Clements ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Body Weight ◽  
Muscle Tissue ◽  
Streptozotocin Diabetes ◽  
Total Body Weight ◽  
Significant Loss ◽  
Diabetic Rat ◽  
Adult Rats ◽  
Organ Specific ◽  
Total Body

Adult male Fisher rats injected with streptozotocin (Stz) to produce diabetes mellitus demonstrated a significant loss of total body weight associated with adipose and muscle tissue wasting. Paradoxically, intestinal mass and length were increased in Stz-treated rats despite catabolism of other tissues. Concomitant with increased intestinal mass, food and water intake increased significantly in Stz-diabetic animals. Renal weight was not reduced despite the fall in total body weight. It is proposed that the adult Stz-diabetic rat responds to a loss of available insulin by polyphagia, polydipsia, and catabolism of adipose and muscle tissue and that a large percentage of available synthetic fuel is devoted to the production of additional intestinal tissue.

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