Contribution of the known subcellular effects of anesthetics to their negative inotropic effect in intact myocardium.
The results of these studies suggest that halothane, in addition to its effect of reducing the trans-sarcolemmal Ca2+ influx, has a direct effect on the function of the sarcoplasmic reticulum by making the organelle leaky to Ca2+ and reducing the amount of Ca2+ stored. Isoflurane, on the other hand, does not appear to make the sarcoplasmic reticulum leaky to Ca2+. In fact, our observations suggest that isoflurane makes the sarcoplasmic reticulum less leaky to Ca2+. Halothane may enhance the reduction in the myofibrillar response to activator Ca2+ when the muscle fiber length is shortened. Thiopental appears to reduce the trans-sarcolemmal Ca2+ influx without reducing the amount of Ca2+ stored in the sarcoplasmic reticulum.
Komai
H
H
Department of Anesthesiology, University of Wisconsin, Madison 53792.
Rusy
B F
BF
D000777:Anesthetics / Q000494:pharmacology*; D000818:Animals; D003864:Depression, Chemical; D006221:Halothane / Q000494:pharmacology; D066298:In Vitro Techniques; D007530:Isoflurane / Q000494:pharmacology; D009200:Myocardial Contraction / Q000187:drug effects*; D009210:Myofibrils / Q000187:drug effects / Q000378:metabolism; D011817:Rabbits; D012433:Ryanodine / Q000494:pharmacology; D012519:Sarcoplasmic Reticulum / Q000187:drug effects / Q000378:metabolism; D013347:Subcellular Fractions / Q000187:drug effects*
D000777:Anesthetics; D012433:Ryanodine; D007530:Isoflurane; D006221:Halothane