Thiopental does not alter Ca2+ uptake by cardiac sarcoplasmic reticulum.
The effect of thiopental on Ca2+ uptake by cardiac sarcoplasmic reticulum (SR) isolated from the rabbit was examined to clarify the role of the sarcoplasmic reticulum in the negative inotropic action of thiopental. Thiopental, from 0 to 378 microM, did not alter the rate of Ca2+ uptake by the SR. We also compared the ATP dependence of Ca2+ uptake in the presence and absence of 284 microM thiopental. The Km for ATP and the Vmax of Ca+ uptake were unaffected by thiopental. It is concluded that thiopental does not alter Ca2+ uptake by the SR and that the negative inotropic effects of thiopental occur at other sites in the myocardial cell.
Blanck
T J
TJ
Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, Maryland.
Stevenson
R L
RL
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D066298:In Vitro Techniques; D009200:Myocardial Contraction / Q000187:drug effects; D009206:Myocardium / Q000378:metabolism*; D011817:Rabbits; D012519:Sarcoplasmic Reticulum / Q000378:metabolism*; D013874:Thiopental / Q000494:pharmacology*
D013874:Thiopental; D002118:Calcium