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.

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.

scholarly journals MICROBODIES IN EXPERIMENTALLY ALTERED CELLS

1967 ◽  
Vol 35 (1) ◽  
pp. 127-152 ◽  
Author(s):  
Donald Svoboda ◽  
Harold Grady ◽  
Daniel Azarnoff
Keyword(s):  
Female Rats ◽  
Male Rats ◽  
Hypolipidemic Effect ◽  
Kidney Cells ◽  
Experimental Conditions ◽  
Hypolipidemic Drug ◽  
Sufficient Cause ◽  
Monkey Liver ◽  
Liver And Kidney ◽  
Sustained Increase

A rapid and sustained increase in the number of microbodies in liver and kidney cells can be induced in male rats by ethyl chlorophenoxyisobutyrate (CPIB), a hypolipidemic drug. This phenomenon permits investigation of several aspects of microbody behavior in experimental conditions. Reversal experiments demonstrate that liver cells revert to normal between 2 and 3 weeks after withdrawal of CPIB and that one of the mechanisms for removal of excess microbodies is their incorporation into structures indistinguishable from lysosomes. In a state of rapid cell division, such as that present during liver regeneration, microbody proliferation apparently occupies a high biological priority. In necrotic or degenerating cells microbody structure remains relatively normal. The increase in microbodies induced by CPIB is inhibited by chloramphenicol. No increase in microbodies occurred in female rats or in chickens, guinea pigs, or rabbits at the dosage used (0.25% in diet). No changes in microbodies were seen in monkey liver. Catalase activity was generally parallel to the numerical response in microbodies. Additional observations suggest that the microbody response to CPIB is not related to hepatomegaly induced by this agent but may be related to the hypolipidemic effect of CPIB, though hypolipidemia per se is not a specific or sufficient cause of microbody proliferation.

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.

Effects of the new prolactin-producing tumour 7315b on gonadotrophin secretion in adult male and female rats

1989 ◽  
Vol 120 (2) ◽  
pp. 261-268 ◽  
Author(s):  
A. Kooy ◽  
R. F. A. Weber ◽  
M. P. Ooms ◽  
J. T. M. Vreeburg
Keyword(s):  
Serum Levels ◽  
Female Rats ◽  
Male Rats ◽  
Suitable Model ◽  
Intact Male ◽  
Adult Rats ◽  
Male And Female ◽  
Male And Female Rats ◽  
Serum Lh ◽  
Gonadotrophin Secretion

ABSTRACT The effects of the transplantable purely prolactin-secreting tumour 7315b on serum gonadotrophins were studied in adult rats. Possible contributions of the adrenals to the tumour-induced inhibition of serum LH and FSH were evaluated. The suppressive actions of tumour 7315b on serum gonadotrophins in gonadectomized plus adrenalectomized male and female rats were compared. Within 4 weeks after inoculation of tumour 7315b in intact male rats very high levels of prolactin and decreased serum levels of gonadotrophins and testosterone were recorded. At autopsy reduced weights of testes and accessory sex organs and slightly increased adrenal weights were found. In addition, in animals treated with a small testosterone-filled capsule after castration, tumour 7315b reduced serum concentrations of LH and FSH. Adrenalectomy did not prevent this suppressive action of the tumour on the post-castration rise of serum gonadotrophins. Suppression of serum gonadotrophins during hyperprolactinaemia was greater in gonadectomized plus adrenalectomized female rats than in male rats, indicating that the degree of the tumour-induced suppression of LH and FSH after castration is determined to a large extent by the sex of the animal. The purely prolactin-secreting tumour 7315b has therefore been shown to be a suitable model for studying the effects of severe hyperprolactinaemia on the pituitary-gonadal axis in rats. Journal of Endocrinology (1989) 120, 261–268

INDUCTION OF GOITRE BY PTU OR KClO4 IN MALE AND FEMALE RATS. EFFECT OF GONADECTOMY

1973 ◽  
Vol 74 (1) ◽  
pp. 88-104 ◽  
Author(s):  
T. Jolín ◽  
M. J. Tarin ◽  
M. D. Garcia
Keyword(s):  
Iodine Content ◽  
High Plasma ◽  
Disc Electrophoresis ◽  
Female Rats ◽  
Male Rats ◽  
Adult Rats ◽  
Male And Female ◽  
Glucose Levels ◽  
Male And Female Rats ◽  
Tsh Levels

ABSTRACT Male and female rats of varying ages were placad on a low iodine diet (LID) plus KClO4 or 6-propyl-2-thiouracil (PTU) or on the same diet supplemented with I (control rats). Goitrogenesis was also induced with LID plus PTU in gonadectomized animals of both sexes. The weight of the control and goitrogen treated animals, and the weight and iodine content of their thyroids were determined, as well as the plasma PBI, TSH, insulin and glucose levels. The pituitary GH-like protein content was assessed by disc electrophoresis on polyacrylamide gels. If goitrogenesis was induced in young rats of both sexes starting with rats of the same age, body weight (B.W.) and pituitary growth hormone (GH) content, it was found that both the males and females developed goitres of the same size. On the contrary, when goitrogenesis was induced in adult animals, it was found that male rats, that had larger B.W. and pituitary GH content than age-paired females, developed larger goitres. However, both male and female rats were in a hypothyroid condition of comparable degree as judged by the thyroidal iodine content and the plasma PBI and TSH levels. When all the data on the PTU or KClO4-treated male and female rats of varying age and B.W. were considered together, it was observed that the weights of the thyroids increased proportionally to B.W. However, a difference in the slope of the regression of the thyroid weight over B.W. was found between male and female rats, due to the fact that adult male rats develop larger goitres than female animals. In addition, in the male rats treated with PTU, gonadectomy decreased the B.W., pituitary content of GH-like protein and, concomitantly, the size of the goitre decreased; an opposite effect was induced by ovariectomy on the female animals. However, when goitrogenesis was induced in weight-paired adult rats of both sexes, the male animals still developed larger goitres than the females. Among all the parameters studied here, the only ones which appeared to bear a consistent relationship with the size of the goitres in rats of different sexes, treated with a given goitrogen, were the rate of body growth and the amount of a pituitary GH-like protein found before the onset of the goitrogen treatment. Moreover, though the pituitary content of the GH-like protein decreased as a consequence of goitrogen treatment, it was still somewhat higher in male that in female animals. The present results suggest that GH may somehow be involved in the mechanism by which male and female rats on goitrogens develop goitres of different sizes, despite equally high plasma TSH levels.

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)

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.

Sensitizing effect of treatment with estrogens on TSH response to TRH in male rats.

1977 ◽  
Vol 233 (3) ◽  
pp. E235 ◽  
Author(s):  
A De Lean ◽  
F Labrie
Keyword(s):  
Estradiol Benzoate ◽  
Thyroid Stimulating Hormone ◽  
Prolactin Secretion ◽  
Male Rats ◽  
Intact Male ◽  
Basal Plasma ◽  
Prolactin Content ◽  
High Doses ◽  
Sensitizing Effect ◽  
Plasma Prl

Daily administration of estradiol benzoate (10 microgram/100 g body wt) to intact male rats led to a twofold increase of the plasma TSH (thyroid-stimulating hormone) response to thyrotropin-releasing hormone (TRH) after 4 and 7 days of treatment whereas the basal plasma TSH level was not affected. The basal plasma PRL concentration and the PRL response to TRH were both markedly increased by estrogen treatment. The TSH pituitary content remained unchanged, whereas the PRL pituitary content increased in parallel with the effect on PRL secretion. Treatment with estrogens for 1 wk sensitized the TSH secretory response to low doses of TRH (10 ng), whereas no significant effect on the response was found at high doses of the neurohormone. The present data show that the stimulatory effect of estrogens on the TSH response to TRH is due to true sensitization of the thyrotrophs to the action of the neurohormone, whereas that on prolactin secretion can result partly from increased pituitary prolactin content.

Cytoplasmic estrogen, but not progestin, binding sites in male rat adipose tissues

1980 ◽  
Vol 239 (4) ◽  
pp. E237-E237
Keyword(s):  
Binding Sites ◽  
Specific Binding ◽  
Estradiol Benzoate ◽  
Female Rats ◽  
Male Rats ◽  
Male Rat ◽  
Adipose Tissues ◽  
Body Fat Content ◽  
Estrogen Binding ◽  
Fat Pads

Male rat adipose tissues contain cytoplasmic estrogen binding sites comparable to those found in females. This bindng is of high affinity (Kd = 1.7 x 10(-10) M) and is estrogen specific. Binding of 17 beta-estradiol was inhibited by radioinert estrogens (17 beta-estradiol and R 2858) but not by other steroids (progesterone, 5 alpha-dihydrotestosterone, and corticosterone). Estrogen binding sites were found in all fat pads studied, but levels were highest in the epididymal pads. Treatment of female rats with 17 beta-estradiol benzoate (E2B) induced cytoplasmic progestin receptors in adipose tissues, but in three separate experiments, E2B treatment (20 microgram/day for 3 days) failed to induce measurable progestin ([3H]R 5020) binding sites in males. E2B treatment reduced lipoprotein lipase (LPL) activity by approximately 75% in epididymal (male) and parametrial (female) fat pads. Concurrent progesterone treatment increased parametrial LPL activity in E2B-treated females, but progesterone had no effect on epididymal fat pad LPL activity in males. These findings are consistent with the hypothesis that in male rats aromatized (estrogenic) metabolites of testosterone may reduce body fat content and alter lipid metabolism by direct actions on adipose tissues.

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