Red blood cells Ca2+ pump is not altered in essential hypertension of humans and Kyoto rats.
The kinetic parameters of the Ca2+ pump were assessed in red blood cells of essential hypertensive subjects as compared to their respective controls. Uphill Ca2+ efflux was investigated in Ca2+ -saturated intact red blood cells using a new method recently developed for human red cells (Dagher,G. and Lew, V. J. Physiol. (London), in the press). 45Ca-equilibrated cells were obtained using ionophore A23187 and Ca2+ efflux was assessed after addition of excess CoCl2 which totally inhibits Ca2+ influx and thus exposes uphill Ca2+ extrusion by the pump. The results comprise methodological aspects of the use of this technique in rat red blood cells. The determination of the maximal velocity and the Ca2+ concentration for half-maximal stimulation (KCa 0.5) did not reveal any alteration in essential hypertensives and spontaneously hypertensive rats as compared to their controls.
D000328:Adult; D000368:Aged; D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000097:blood*; D002132:Calcium Radioisotopes; D003035:Cobalt / Q000494:pharmacology; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D006973:Hypertension / Q000097:blood*; D007473:Ion Channels / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D008875:Middle Aged; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D014638:Vanadates / Q000494:pharmacology
D002132:Calcium Radioisotopes; D007473:Ion Channels; D000001:Calcimycin; D003035:Cobalt; D014638:Vanadates; C018021:cobaltous chloride; D002118:Calcium