title: Comparative effects of (+)- and (-)-isomers of propranolol and INPEA on (+)-tubocurarine- and succinylcholine-induced neuromuscular blockade.
abstract: The effects of the (+)- and (-)-isomers of propranolol and INPEA on the neuromuscular blocking action of (+)-tubocurarine and succinylcholine were studied in the tibialis anterior-peroneal nerve preparation of the rabbit and the isolated phrenic nerve-diaphragm preparation of the rat. (+)-Tubocurarine-induced neuromuscular blockade was intensified by (+)- and (-)-isomers of INPEA whereas it was unaffected by isomers of propranolol in both preparations. In the rabbit tibialis anterior-peroneal nerve preparation, only the (-)-isomers of propranolol and INPEA increased the duration of succinylcholine-induced neuromuscular blockade without affecting its magnitude. Higher doses of both (+)- and (-)-isomers of propranolol and INPEA potentiated succinylcholine-induced blockade in the rat phrenic nerve-diaphragm preparation. The results obtained indicate that only the increase in duration of succinylcholine-induced blockade with beta-adrenoceptor blockers can be related to beta-blocking property of these compounds.
mesh_terms: D000818:Animals; D003964:Diaphragm / Q000187:drug effects; D004558:Electric Stimulation; D004983:Ethanolamines / Q000494:pharmacology*; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects; D009469:Neuromuscular Junction / Q000187:drug effects*; D010543:Peroneal Nerve / Q000502:physiology; D010791:Phrenic Nerve / Q000502:physiology; D011433:Propranolol / Q000494:pharmacology*; D011817:Rabbits; D051381:Rats; D013237:Stereoisomerism; D013390:Succinylcholine / Q000494:pharmacology*; D013997:Time Factors; D014403:Tubocurarine / Q000494:pharmacology*
chemical_list: D004983:Ethanolamines; D011433:Propranolol; D013390:Succinylcholine; D014403:Tubocurarine