Testicular dysfunction in experimental chronic renal insufficiency: a deficiency of nocturnal pineal N-acetyltransferase activity.
Biochemical correlates of neuroendocrine/gonadal function and nocturnal levels of serotonin N-acetyltransferase (NAT) activity were determined in partially nephrectomized (PNx), male, Long Evans rats following a 5-week period of chronic renal insufficiency (CRI). PNx animals demonstrated two to four-fold elevations in urea nitrogen and three to four-fold reductions (P less than 0.02) in plasma total testosterone concentrations as compared to sham-operated controls. The pituitary LH contents of PNx rats were decreased to approximately 60% of the control value (P less than 0.05). There were no differences in plasma prolactin levels between the control and PNx groups either at mid-day or in the middle of the night. Nocturnal pineal NAT activity in PNx rats was markedly reduced to approximately 20% of the control value (P less than 0.001). Similar evidence of gonadal dysfunction (reduced plasma total testosterone and testes testosterone content) and a significant decrease in night-time levels of pineal NAT activity were also observed after 13 weeks of CRI in PNx rats of the Sprague-Dawley strain that were housed under a different photoperiod. These results suggest that pineal gland dysfunction is a feature of CRI in the PNx model. Such an abnormality might contribute to the pathogenesis of gonadal dysfunction in CRI.
Department of Pathology, Loyola University Stritch School of Medicine, Maywood, IL 60153.
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Holmes
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Hojvat
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Kahn
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Bermes
D000818:Animals; D004195:Disease Models, Animal; D007676:Kidney Failure, Chronic / Q000378:metabolism*; D008027:Light; D007986:Luteinizing Hormone / Q000032:analysis; D008297:Male; D010870:Pineal Gland / Q000201:enzymology*; D011388:Prolactin / Q000032:analysis; D051381:Rats; D011919:Rats, Inbred Strains; D013733:Testicular Diseases / Q000378:metabolism*; D013739:Testosterone / Q000032:analysis
D013739:Testosterone; D011388:Prolactin; D007986:Luteinizing Hormone