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.
Holmes
E W
EW
Department of Pathology, Loyola University Stritch School of Medicine, Maywood, IL 60153.
Hojvat
S A
SA
Kahn
S E
SE
Bermes
E W
EW
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