Effect of age and testosterone on the vasopressin and aquaporin responses to dehydration in Fischer 344/Brown-Norway F1 rats.
To determine if the aging-associated decline in testosterone results in attenuated vasopressin (VP) responses to dehydration, testosterone implants were given to aged male Fischer 344Brown-Norway F1(F344BNF1) rats. Water deprivation caused comparable dehydration, increased plasma VP (pVP), and decreased posterior pituitary (PP) VP content in 4-, 15-, and 28-month-old rats. Dehydration increased VP mRNA content of supraoptic nuclei only at 4 months, whereas VP mRNA length was increased at both 4 and 15 months of age. The elevated pVP in the water-deprived aged rats indicates that even without an increase in VP mRNA content, PP VP storage was adequate to maintain elevated pVP. Dehydration increased aquaporin-2 content at 4, but not at 15 or 28 months of age, suggesting decreased renal responsiveness to VP. Testosterone replacement did not produce dehydration-induced increases in VP mRNA or aquaporin-2. Therefore, testosterone deficiency does not result in altered VP responses to dehydration in aged F344BNF1 rats.
Catudioc-Vallero
J
J
Department of Physiology and Biophysics, Finch University of Health Sciences/The Chicago Medical School, North Chicago, Illinois 60064, USA.
Sands
J M
JM
Klein
J D
JD
Sidorowicz
H E
HE
Sladek
C D
CD
D000375:Aging / Q000502:physiology*; D000704:Analysis of Variance; D000818:Animals; D020346:Aquaporins / Q000378:metabolism*; D015152:Blotting, Northern; D015153:Blotting, Western; D003681:Dehydration / Q000378:metabolism / Q000503:physiopathology*; D004343:Drug Implants; D007679:Kidney Medulla / Q000378:metabolism; D008297:Male; D010904:Pituitary Gland, Posterior / Q000378:metabolism; D011374:Progesterone / Q000097:blood / Q000378:metabolism; D012313:RNA / Q000032:analysis; D011863:Radioimmunoassay; D051381:Rats; D011914:Rats, Inbred BN; D011916:Rats, Inbred F344; D013739:Testosterone / Q000494:pharmacology*; D014667:Vasopressins / Q000097:blood / Q000378:metabolism*
D020346:Aquaporins; D004343:Drug Implants; D014667:Vasopressins; D013739:Testosterone; D011374:Progesterone; D012313:RNA