Inhibition of Na+-Ca2+ exchange mechanism in cardiac sarcolemmal vesicles by harmaline.
1. Harmaline was found to inhibit the Na+-Ca2+ exchange mechanism present in cardiac sarcolemmal vesicles. 2. The inhibition was dose-dependent and was observed in the range 10(-5) M-10(-2) M harmaline. 3. The effect was demonstrated on both 45Ca2+-uptake and 45Ca2+-efflux. 4. The observed Ki value for harmaline inhibition of 45Ca2+-uptake was found to be 2.5 X 10(-4) M.
D000470:Alkaloids / Q000494:pharmacology*; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002132:Calcium Radioisotopes; D002352:Carrier Proteins / Q000378:metabolism*; D002417:Cattle; D006246:Harmaline / Q000494:pharmacology*; D007700:Kinetics; D009206:Myocardium / Q000378:metabolism*; D012508:Sarcolemma / Q000187:drug effects / Q000378:metabolism*; D019831:Sodium-Calcium Exchanger
D000470:Alkaloids; D002132:Calcium Radioisotopes; D002352:Carrier Proteins; D019831:Sodium-Calcium Exchanger; D006246:Harmaline; D002118:Calcium