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Biomedical subjects

M Kurcz

Publications and source records attributed to M Kurcz.

At least 37 records · Page 2Linked to original sources
PubMed1977

Effects of starvation in rats on serum levels of follicle stimulating hormone, luteinizing hormone, thyrotropin, growth hormone and prolactin; response to LH-releasing hormone and thyrotropin-releasing hormone.

Adult male Sprague-Dawley rats averaging 300 g each were subjected to complete food removal for 7 days (acutely starved), 7 days complete food removal followed by 2 weeks of 1/4 ad libitum food intake (chronically strved), 7 days complete food removal and 2 weeks of 1/4 ad libitum intake followed by ad libitum feeding for 7 days (refed), or fed ad libitum throughout (controls). Serum LH, FSH, TSH, PRL, and GH levels were measured by radioimmunoassays for each group of rats. The in vivo response to the combination of synthetic LHRH and TRH also was tested in each group of rats. Circulating LH, TSH, GH, and PRL were significantly depressed in acutely and chronically starved rats, and FSH was lowered only in acutely starved rats. After 7 days of refeeding, serum levels of LH and FSH were significantly greater than in ad libitum fed controls, PRL returned to control levels, and TSH and GH increased but were still below control levels. After LHRH + TRH injection serum LH and TSH were increased significantly in all groups of rats, FSH and PRL rose in acutely but not in chronically starved rats, and GH was not elevated in any group. The increases in serum LH, FSH, TSH and prolactin in response to LHRH + TRH injection in acutely or chronically starved rats were equal to or greater than in the ad libitum fed controls. These data indicate that severe reductions in food intake result in decreased release of at least 5 anterior pituitary hormones, and this is due primarily to reduced hypothalamic stimulation rather than to inability of the pituitary to secrete hormones.

Adrenal Glands↗
PubMed1976

Correlation between sexual steroid effect and activity changes and isoenzyme distribution of lactate dehydrogenase (EC 1.1.1.27) in rat anterior pituitary.

Sexual steroid feed-back is a fundamental regulating factor oification of pituitary metabolism in rat. Oestrogen synthesis and/or activity of M subunif testosterone, in males testosterone treatment as well as lack of oestrogen result in characteristic pituitary LDH activity and isoenzyme distribution. Physiological doses of sexual steroids affect, directly or indirectly, pituitary LDH activity, oxydative metabolism, and imply different biochemical bases for the polypeptide hormone production in the anterior pituitary gland.

Animals↗
PubMed1976

Sexual difference in pituitary pyruvic acid content, as well as of lactic acid/pyruvic acid quotient.

The lactic acid/pyruvic acid quotient of rat anterior pituitary varies betweeen 30 and 80. The dominance of lactic acid is in accordance with the earlier observation that pituitary lactate dehydrogenase isoenzymes in rat are made up, in majority, of M subunits. The pituitary lactic acid concentration in female and male animals shows no appreciable difference and does not change 2 and 4 weeks after castration. In males the pituitary pyruvic acid concentration was almost double of that in females. Pyruvic acid content increases after ovariectomy and decreases after orchidectomy. The sexual differences having been observed in lactic acid/pyruvic acid quotient are in correlation with the discrepancy of pyruvic acid concentration.

Animals↗
PubMed1975

Compensatory hypertrophy in radiothyroidectomized dwarf rats.

The aim of the study was to clarify whether growth hormone and thyroid hormones play a role in compensatory organ hypertrophy. Radiothyroidectomized dwarf rats with serious disorder of growth hormone production due to the loss of thyroid function were used in the experiments. As regards growth hormone production these animals may be considered as having been "hypophysectomized". The loss of thyroid function and growth hormone deficiency did not affect the degree of compensatory hypertrophy of the kidney, the adrenal and the gonad. The observation indicates that the hormones under study are not of decisive importance in the mechanism of compensatory organ enlargement. Further investigations are needed to clarify whether organ enlargement in the hypometabolic rat occurring at the level observed in the controls is associated with enhanced function.

Adrenal Gland Diseases↗
PubMed1975

Growth hormone and prolactin content of hyperplastic anterior pituitary of dehydroepiandrosterone treated rats.

30 days after implantation of 80 mg dehydroepiandrosterone (androst-5-en-3betaol-17-one) hyperplastic enlargement of the anterior pituitary has been observed in about 80 per cent of the female rats. There was an important increase of prolactin content, growth hormone content remained unchanged. The mentioned alterations were found to be reversible, since regression was observed after DEA treatment exceeding 30 days. In females developing no hyperplasia pituitary growth hormone contentration and content has been decreased, prolactin content remained unchanged. In male rats on identical treatment no change of pituitary weight, growth hormone and prolactin concent has been found. The results suggest that, under physiological conditions, DEA does not affect pituitary growth hormone and prolactin content, however response to pharmacological doses was different in male and female rats.

Animals↗