Separation and characteristics of inside-out and right side-out vesicles from a rat cardiac sarcolemma preparation.
Purified cardiac sarcolemma (SL) vesicles are highly suitable to study various Ca2+-transport systems present in the SL. We describe in this paper the separation of the Inside-Out (IO) and Right side-Out (RO) oriented vesicle subpopulations from a purified rat heart SL preparation. The isolated subfractions were characterized with respect to the number of beta-adrenergic binding sites and the Ca2+-uptake and (Ca2+-Mg2+)-ATPase activities. It was found that the Ca2+-uptake and the (Ca2+-Mg2+)-ATPase activities reside in the IO fraction and are virtually absent in the RO fraction, confirming that the active Ca2+-uptake represents the outward directed sarcolemmal Ca2+-flux.
D000818:Animals; D017301:Ca(2+) Mg(2+)-ATPase / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D000252:Calcium-Transporting ATPases / Q000378:metabolism; D002458:Cell Fractionation; D004082:Dihydroalprenolol / Q000378:metabolism; D007700:Kinetics; D009206:Myocardium / Q000378:metabolism* / Q000648:ultrastructure; D051381:Rats; D011919:Rats, Inbred Strains; D011943:Receptors, Adrenergic, beta / Q000378:metabolism; D012508:Sarcolemma / Q000378:metabolism / Q000648:ultrastructure*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism
D011943:Receptors, Adrenergic, beta; D004082:Dihydroalprenolol; D017301:Ca(2+) Mg(2+)-ATPase; D000252:Calcium-Transporting ATPases; D000254:Sodium-Potassium-Exchanging ATPase; D002118:Calcium