Age-related change in parathyroid hormone-dependent cyclic AMP formation in rat kidney.
Parathyroid hormone (PTH) dependent cyclic AMP (cAMP) accumulation was evaluated in renal cortex from 2- and 12-month-old rats. Basal cAMP was lower, and responses to PTH were greater at all concentrations of hormone in kidney from 2-month-old rats. This difference was obliterated by prior removal of parathyroid glands. cAMP responses to calcitonin and both basal and hormone-stimulated adenylate cyclase activity were the same at both ages. The results suggest progressive loss of responsiveness to PTH with age, but at a site other than the receptor-adenylate cyclase complex. Blunted cAMP accumulation in year-old rats most likely reflects agonist-specific desensitization.
D000262:Adenylyl Cyclases / Q000378:metabolism; D000375:Aging; D000818:Animals; D002116:Calcitonin / Q000494:pharmacology; D002118:Calcium / Q000097:blood; D000242:Cyclic AMP / Q000096:biosynthesis*; D066298:In Vitro Techniques; D007672:Kidney Cortex / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D010280:Parathyroid Glands / Q000502:physiology; D010281:Parathyroid Hormone / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains
D010281:Parathyroid Hormone; D002116:Calcitonin; D000242:Cyclic AMP; D000262:Adenylyl Cyclases; D002118:Calcium