title: Control of low Km cyclic adenosine 3',5'-monophosphate-phosphodiesterase in prostate and heart of adult and aged rats.
abstract: The activity of low Km cAMP-phosphodiesterase (PDE) was determined in extracts of prostate and heart of adult (10-12 months old) and aged (32-35 months old) Sprague-Dawley rats; the enzyme's response to endogenous inhibitors extracted from the two organs was analyzed by kinetic studies. Different mechanisms of inhibition, non-competitive in prostate and competitive in heart extracts, indicate organ-specificity of the inhibitor. The decreased PDE activity in organ extracts of aged rats and its continued sensitivity to the endogenous inhibitor suggest an age-associated impairment of the tissues' ability to terminate cAMP-mediated signals.
mesh_terms: D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000375:Aging / Q000378:metabolism*; D000818:Animals; D007700:Kinetics; D008297:Male; D009206:Myocardium / Q000201:enzymology*; D011467:Prostate / Q000201:enzymology*; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D015105:3',5'-Cyclic-AMP Phosphodiesterases