title: The effects of sevoflurane on contractile and electrophysiologic properties in isolated guinea pig papillary muscles.
abstract: We examined, in guinea pig papillary muscles, whether the negative inotropic effect of sevoflurane is due to the depression of the influx of extracellular Ca2+ or to inhibition of the availability of intracellularly stored Ca2+. Sevoflurane decreased action potential duration and contractile force in a concentration-dependent fashion in normally polarized guinea pig papillary muscles. Sevoflurane produced a depression of contractile force with different rates or patterns of stimulation in the rested state and at low stimulation frequencies. In a potentiated state, sevoflurane did not depress contractile forces. Although sevoflurane decreased action potential duration and contractile force in a concentration-dependent fashion in normal Tyrode's solution, in high K+ Tyrode's solution, it caused a depression of contractile force without a shortening of action potential duration. Sevoflurane also depressed contractile force in normal and high K+ Tyrode's solution with ryanodine 1 microM. Our results suggest that in myocardial contractile force the negative inotropic effect of sevoflurane might be caused by depression of transsarcolemmal Ca2+ influx, accompanied by shortening of the action potential duration.
authors.affiliation: Department of Anesthesiology and Intensive Care, Hokkaido University School of Medicine, Sapporo, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Azuma
authors.forename: C
authors.initials: C
authors.lastname: Matsumura
authors.forename: O
authors.initials: O
authors.lastname: Kemmotsu
mesh_terms: D000200:Action Potentials / Q000187:drug effects; D018685:Anesthetics, Inhalation / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D003864:Depression, Chemical; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D004562:Electrocardiography / Q000187:drug effects*; D004987:Ethers / Q000008:administration & dosage / Q000494:pharmacology*; D006168:Guinea Pigs; D017136:Ion Transport / Q000187:drug effects; D007552:Isotonic Solutions / Q000494:pharmacology; D008738:Methyl Ethers; D009200:Myocardial Contraction / Q000187:drug effects*; D009924:Organ Culture Techniques; D010210:Papillary Muscles / Q000187:drug effects* / Q000378:metabolism; D011188:Potassium / Q000494:pharmacology; D012433:Ryanodine / Q000494:pharmacology; D012508:Sarcolemma / Q000187:drug effects / Q000378:metabolism; D000077149:Sevoflurane
chemical_list: D018685:Anesthetics, Inhalation; D000889:Anti-Arrhythmia Agents; D004987:Ethers; D007552:Isotonic Solutions; D008738:Methyl Ethers; C037692:Tyrode's solution; D012433:Ryanodine; D000077149:Sevoflurane; D011188:Potassium; D002118:Calcium