title: Age-related changes in sensitivity of rat urinary bladder to autonomic agents.
abstract: Experiments were done to determine if age-related changes occur in autonomic regulation of rat urinary bladder. The maximum contractile responses to acetylcholine were 63% and 15% greater in isolated bladders from 29-month and 17-month animals, respectively, as compared to 7-month animals. The amounts of [3H]quinuclidinyl benzilate bound to membrane preparations were 46% and 7% greater. In contrast, no age-related changes were observed in phenylephrine-induced contraction or in isoproterenol-induced relaxation of bladder. Thus, the urinary bladder of aged rats appears to develop increased sensitivity to cholinergic stimuli because of an increase in the number of muscarinic cholinergic receptors.
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000375:Aging; D000818:Animals; D001337:Autonomic Agents / Q000494:pharmacology*; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D010656:Phenylephrine / Q000494:pharmacology; D051381:Rats; D011916:Rats, Inbred F344; D011976:Receptors, Muscarinic / Q000378:metabolism; D001743:Urinary Bladder / Q000187:drug effects* / Q000502:physiology
chemical_list: D001337:Autonomic Agents; D011976:Receptors, Muscarinic; D010656:Phenylephrine; D007545:Isoproterenol; D000109:Acetylcholine