title: Postnatal development of myogenic contractile activity and excitatory innervation of rat urinary bladder.
abstract: Bladder strips from newborn compared with adult rats exhibited marked differences in both myogenic properties and postganglionic excitatory innervation. In the first 2-wk of life myogenic contractile activity progressively changed from a quiescent state (at birth) to the asynchronous contractile activity typical of bladder strips from adult animals. After birth activation of muscarinic cholinoceptors changed the myogenic contractile activity in a manner similar to that observed at later stages of development. Neurogenic contractions of bladders from newborn animals were atropine sensitive in the whole range of frequencies studied. During the first 2 wk the atropine-resistant component of these contractions increased progressively to reach an adult-like condition, i.e., atropine-resistant contractions account for over 90% and approximately 60% of contractions elicited at 0.1 and 1-20 Hz, respectively.
mesh_terms: D000375:Aging; D000818:Animals; D000831:Animals, Newborn / Q000254:growth & development*; D001285:Atropine / Q000494:pharmacology; D004351:Drug Resistance; D004558:Electric Stimulation; D006426:Hemicholinium 3 / Q000494:pharmacology; D018738:Hexamethonium; D006584:Hexamethonium Compounds / Q000494:pharmacology; D009119:Muscle Contraction; D010830:Physostigmine / Q000494:pharmacology; D000644:Quaternary Ammonium Compounds / Q000494:pharmacology; D051381:Rats; D013779:Tetrodotoxin / Q000494:pharmacology; D001743:Urinary Bladder / Q000187:drug effects / Q000254:growth & development* / Q000294:innervation
chemical_list: D006584:Hexamethonium Compounds; D000644:Quaternary Ammonium Compounds; D006426:Hemicholinium 3; D018738:Hexamethonium; D013779:Tetrodotoxin; D001285:Atropine; D010830:Physostigmine; C028530:furtrethonium