Change from beta- to alpha-adrenergic glycogenolysis induced by corticosteroids in female rat liver

1997 ◽  
Vol 273 (1) ◽  
pp. R153-R160
Author(s):  
M. Moriyama ◽  
Y. Nakanishi ◽  
S. Tsuyama ◽  
Y. Kannan ◽  
M. Ohta ◽  
...  
Keyword(s):  
Glucose Production ◽  
Plasma Corticosterone ◽  
Mature Female ◽  
Female Rats ◽  
Male Rats ◽  
Female Rat ◽  
Circadian Variations ◽  
Male And Female ◽  
Male And Female Rats ◽  
The Difference

The conversion of beta- to alpha-adrenergic glycogenolysis by corticosteroids was studied in perfused livers of mature female rats. Isoproterenol stimulated glucose production more effectively in female rats than in male rats, but the difference in its stimulatory effect disappeared in adrenalectomized (ADX) rats, whereas it remained in adrenodemedulated rats. When ADX female rats were treated with dexamethasone sulfate, alpha-responses increased and beta-responses decreased, depending on the concentration of dexamethasone sulfate. The treatment of female rats with 1.5 mg/kg dexamethasone sulfate changed the levels of the alpha- and beta-responses to those observed in male rats, and the changes were associated with changes in the number of receptors. Although periodicity of changes in plasma corticosterone levels was observed in both male and female rats, the extent of circadian variations was significantly lower in female rats during the estrous cycle than in male rats. The variations in plasma corticosterone levels and in both alpha- and beta-responses after ovariectomy approached those in male rats. The results suggest that the level of plasma corticosterone might play an important role in the regulation of the relative levels of alpha- and beta-adrenergic responses in female rats.

scholarly journals Glutathione Conjugates of Ochratoxin a as Biomarkers of Exposure / Glutationski Konjugati Okratoksina A Kao Biomarkeri Izloženosti

2012 ◽  
Vol 63 (4) ◽  
pp. 417-427 ◽  
Author(s):  
Mariana Tozlovanu ◽  
Delphine Canadas ◽  
Annie Pfohl-Leszkowicz ◽  
Christine Frenette ◽  
Robert J. Paugh ◽  
...  
Keyword(s):  
Ochratoxin A ◽  
Rat Kidney ◽  
Female Rats ◽  
Amide Bond ◽  
Male Rats ◽  
Dark Agouti ◽  
Female Rat ◽  
Male And Female ◽  
Male And Female Rats ◽  
Liver And Kidney

AbstractIn the present study the photoreactivity of the fungal carcinogen ochratoxin A (OTA) has been utilised to generate authentic samples of reduced glutathione (GSH) and N-acetylcysteine (NAC) conjugates of the parent toxin. These conjugates, along with the nontoxic OTα, which is generated through hydrolysis of the amide bond of OTA by carboxypeptidase A, were utilised as biomarkers to study the metabolism of OTA in the liver and kidney of male and female Dark Agouti rats. Male rats are more susceptible than female rats to OTA carcinogenesis with the kidney being the target organ. Our studies show that the distribution of OTA in male and female rat kidney is not significantly different. However, the extent of OTA metabolism was greater in male than female rats. Much higher levels of OTα were detected in the liver compared to the kidney, and formation of OTα is a detoxification pathway for OTA. These findings suggest that differences in metabolism between male and female rats could provide an explanation for the higher sensitivity of male rats to OTA toxicity

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.

HYPOTHALAMIC LUTEINIZING HORMONE RELEASING FACTOR AND CORTICOTROPHIN RELEASING ACTIVITY IN RELATION TO PITUITARY AND PLASMA HORMONE LEVELS IN MALE AND FEMALE RATS

1977 ◽  
Vol 72 (2) ◽  
pp. 195-210 ◽  
Author(s):  
SHARON A. CHIAPPA ◽  
G. FINK
Keyword(s):  
Plasma Corticosterone ◽  
Female Rats ◽  
Male Rats ◽  
Male And Female ◽  
Male And Female Rats ◽  
Protein Binding Assay ◽  
Female Wistar Rats ◽  
Competitive Protein Binding Assay ◽  
Animal House

SUMMARY Hypothalamic corticotrophin releasing (CR) activity and LH-releasing factor (RF) content, and pituitary and plasma LH, FSH and ACTH were measured in adult male and female Wistar rats maintained under 14 h light per day. Hypothalamic LH-RF and pituitary and plasma hormones were estimated by radioimmunoassay while CR-activity was assessed by the amount of ACTH released from hemipituitaries in vitro. Two experiments were carried out on male animals. In the first, some of the animals were kept in a room, distant from the animal house, in which the lighting was reversed with respect to the external environment. In animals exposed to the reversed lighting régime, hypothalamic LH-RF content and pituitary gonadotrophin concentrations were significantly lower than the values in male rats kept in the animal house where they were in close proximity to female rats. In the second experiment, which was carried out on animals which had all been kept in the animal house, there were no significant differences between the LH-RF contents measured at 3–4 h intervals throughout the day. Pituitary LH and FSH contents, but not concentrations, were significantly increased at 12.00 h. There was little difference between the experiments in CR-activity, plasma ACTH concentrations and profiles of pituitary ACTH content and concentration. As expected there was a diurnal rhythm in plasma corticosterone concentrations (determined by competitive protein-binding assay) with the peak occurring between 15.00 and 18.00 h. The profiles of plasma and pituitary ACTH were similar to that of plasma corticosterone. Corticotrophin releasing activity dropped significantly between 12.00 and 16.00 h, but remained steady at the other times.

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.

Liver glycogenolysis during exercise in adrenodemedullated male and female rats

1986 ◽  
Vol 251 (6) ◽  
pp. R1151-R1155
Author(s):  
W. W. Winder ◽  
S. F. Loy ◽  
D. S. Burke ◽  
S. J. Hawkes
Keyword(s):  
Adrenergic Receptor ◽  
Mature Female ◽  
Female Rats ◽  
Male Rats ◽  
Plasma Epinephrine ◽  
Male And Female ◽  
Male And Female Rats ◽  
Liver Glycogenolysis ◽  
Stimulation Of

Previous studies have shown that adrenodemedullation has no effect on the rate of liver glycogenolysis during exercise in male rats. Mature female rats have been reported to have a higher hepatic beta-adrenergic receptor activity than do male rats of the same age. The present study was undertaken to determine the role of plasma epinephrine in stimulating liver glycogenolysis during exercise in female rats. Both male and female rats were adrenodemedullated or sham operated. Three weeks later rats were run for 60 min at 21 m/min up a 15% grade. The rate of liver glycogenolysis during exercise was not affected by adrenodemedullation in either female rats or male rats. Hepatic adenosine 3',5'-cyclic monophosphate increased to approximately the same extent in sham operated as in adrenodemedullated female rats during exercise. Adrenodemedullation caused a significant reduction in the amount of glycogen utilized by the soleus muscle and in the degree of hyperglycemia during exercise. We conclude that epinephrine is unessential for stimulation of liver glycogenolysis during exercise in either male or female rats.

SERUM CONCENTRATIONS OF TESTOSTERONE, OESTROGENS, LUTEINIZING HORMONE AND FOLLICLE-STIMULATING HORMONE IN MALE AND FEMALE RATS DURING THE CRITICAL PERIOD OF NEURAL SEXUAL DIFFERENTIATION

1979 ◽  
Vol 80 (1) ◽  
pp. 103-110 ◽  
Author(s):  
S. F. PANG ◽  
A. R. CAGGIULA ◽  
V. L. GAY ◽  
R. L. GOODMAN ◽  
C. S. F. PANG
Keyword(s):  
Post Partum ◽  
Serum Levels ◽  
Female Rats ◽  
Male Rats ◽  
Female Rat ◽  
Serum Concentrations ◽  
Male And Female ◽  
Rat Pups ◽  
Male And Female Rats ◽  
Sampling Times

Untreated male and female rat pups were killed 1–5 days post partum and the serum concentrations of testosterone, oestrogens, LH and FSH were determined by radioimmunoassay. At all five sampling times, the serum concentrations of testosterone in male rats were about three times higher than those in female rats, but serum levels of oestrogens did not differ between the sexes. Serum concentrations of LH and FSH were lower in male than in female pups. In another study, rats were decapitated 1–10 days after birth and serum concentrations of testosterone were determined with a different radioimmunoassay. Again, at all four sampling times, the concentration of testosterone was significantly higher in the male than in the female pups.

SEX STEROIDS STIMULATE THE ACTIVITY OF HYPOTHALAMIC ARYLAMIDASES IN THE RAT

1974 ◽  
Vol 76 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Herbert Kuhl ◽  
Christian Rosniatowski ◽  
Siang-An Oen ◽  
Hans-Dieter Taubert
Keyword(s):  
Glutamic Acid ◽  
Sex Steroids ◽  
Specific Pattern ◽  
Steroid Treatment ◽  
Female Rats ◽  
Male Rats ◽  
Female Rat ◽  
Experimental Conditions ◽  
Male And Female ◽  
Male And Female Rats

ABSTRACT The effect of steroid treatment on the activity of hypothalamic arylamidases in male and female rats was investigated. A new and improved method for the assay of arylamidase activity utilizing L-α-amino acid-p-nitroanilides as substrates is presented. The influence of varying experimental conditions on the activity of hypothalamic arylamidases hydrolyzing the p-nitroanilides of cystine, glutamic acid, alanine, tyrosine, leucine, and phenylalanine, such as changes of substrate and enzyme concentration, temperature, incubation time, and pH, were tested. There was a sex-dependent response in the activity of hypothalamic arylamidases to treatment of the rats with sex steroids. In female rats, the injection of 7 μg of ethinyloestradiol was followed 16 hours later by a significant rise of L-cystine and L-glutamic acid arylamidase activity. In male rats, the injection of testosterone and of ethinyloestradiol respectively brought about a general stimulation of all enzyme activities. This indicates that this enzyme system of the male and female rat hypothalamus responds to steroid treatment of the animals with a sex-specific pattern.

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.

GONADOTROPHIN PATTERNS IN MALE AND FEMALE RATS:

1968 ◽  
Vol 58 (4) ◽  
pp. 600-612 ◽  
Author(s):  
Robert Boyd ◽  
Donald C. Johnson
Keyword(s):  
Ascorbic Acid ◽  
Testosterone Propionate ◽  
Female Rats ◽  
Female Rat ◽  
Feedback Effects ◽  
Male And Female ◽  
Prostate Weight ◽  
Male And Female Rats ◽  
Males And Females ◽  
Normal Males

ABSTRACT The effects of various doses of testosterone propionate (TP) upon the release of luteinizing hormone (LH or ICSH) from the hypophysis of a gonadectomized male or female rat were compared. Prostate weight in hypophysectomized male parabiotic partners was used to evaluate the quantity of circulating LH. Hypophyseal LH was measured by the ovarian ascorbic acid depletion method. Males castrated when 45 days old secreted significantly more LH and had three times the amount of pituitary LH as ovariectomized females. Administration of 25 μg TP daily reduced the amount of LH in the plasma, and increased the amount in the pituitary gland, in both sexes. Treatment with 50 μg caused a further reduction in plasma LH in males, but not in females, while pituitary levels in both were equal to that of their respective controls. LH fell to the same low level in partners of males or females receiving 100 μg TP. When gonadectomized at 39 days, males and females had the same amount of plasma LH, but males had more stored hormone. Pituitary levels were unchanged from controls following treatment with 12.5, 25 or 50 μg TP daily, but plasma values dropped an equal amount in both sexes with the latter two doses. Androgenized males or females, gonadectomized when 39 days old, were very sensitive to the effects of TP and plasma LH was significantly reduced with 12.5 μg daily. Pituitary LH in androgenized males was higher than that of normal males but was reduced to normal by small amounts of TP. The amount of stored LH in androgenized females was not different from that of normal females and it was unchanged by any dose of TP tested. Results are consistent with the conclusion that the male hypothalamic-hypophyseal axis is at least as sensitive as the female axis to the negative feedback effects of TP. Androgenization increases the sensitivity to TP in both males and females.

scholarly journals Analysis of sex differences in dietary copper-fructose interaction-induced alterations of gut microbial activity in relation to hepatic steatosis

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ming Song ◽  
Fang Yuan ◽  
Xiaohong Li ◽  
Xipeng Ma ◽  
Xinmin Yin ◽  
...  
Keyword(s):  
Sex Differences ◽  
Microbial Activity ◽  
Hepatic Steatosis ◽  
Female Rats ◽  
Male Rats ◽  
Calorie Intake ◽  
Dietary Copper ◽  
Male And Female ◽  
Male And Female Rats ◽  
Rrna Sequencing

Abstract Background Inadequate copper intake and increased fructose consumption represent two important nutritional problems in the USA. Dietary copper-fructose interactions alter gut microbial activity and contribute to the development of nonalcoholic fatty liver disease (NAFLD). The aim of this study is to determine whether dietary copper-fructose interactions alter gut microbial activity in a sex-differential manner and whether sex differences in gut microbial activity are associated with sex differences in hepatic steatosis. Methods Male and female weanling Sprague-Dawley (SD) rats were fed ad libitum with an AIN-93G purified rodent diet with defined copper content for 8 weeks. The copper content is 6 mg/kg and 1.5 mg/kg in adequate copper diet (CuA) and marginal copper diet (CuM), respectively. Animals had free access to either deionized water or deionized water containing 10% fructose (F) (w/v) as the only drink during the experiment. Body weight, calorie intake, plasma alanine aminotransferase, aspartate aminotransferase, and liver histology as well as liver triglyceride were evaluated. Fecal microbial contents were analyzed by 16S ribosomal RNA (16S rRNA) sequencing. Fecal and cecal short-chain fatty acids (SCFAs) were determined by gas chromatography-mass spectrometry (GC-MS). Results Male and female rats exhibit similar trends of changes in the body weight gain and calorie intake in response to dietary copper and fructose, with a generally higher level in male rats. Several female rats in the CuAF group developed mild steatosis, while no obvious steatosis was observed in male rats fed with CuAF or CuMF diets. Fecal 16S rRNA sequencing analysis revealed distinct alterations of the gut microbiome in male and female rats. Linear discriminant analysis (LDA) effect size (LEfSe) identified sex-specific abundant taxa in different groups. Further, total SCFAs, as well as, butyrate were decreased in a more pronounced manner in female CuMF rats than in male rats. Of note, the decreased SCFAs are concomitant with the reduced SCFA producers, but not correlated to hepatic steatosis. Conclusions Our data demonstrated sex differences in the alterations of gut microbial abundance, activities, and hepatic steatosis in response to dietary copper-fructose interaction in rats. The correlation between sex differences in metabolic phenotypes and alterations of gut microbial activities remains elusive.

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