Devynck M A, Pernollet M G, Nunez A M, Meyer P
Hypertension. 1981 Jul-Aug;3(4):397-403. doi: 10.1161/01.hyp.3.4.397.
Calcium handling by erythrocyte membranes was compared in genetically hypertensive (SHR) and normotensive (WKR) rats by direct measurement of calcium binding, passive influx, and adenosine triphosphate (ATP)-dependent extrusion. The SHR erythrocyte membranes exhibited the following abnormalities: 1) the binding capacity of the high affinity Ca2+-binding sites located on the inner side of the membrane was 0.84 +/- 0.07 nmole/mg protein compared with 1.17 +/- 0.08 nmole/mg protein in WKR, 2) ATP-dependent Ca2+ extrusion, measured as the Ca2+ influx into inside-out vesicles, was also lower than the WKR, as was the La3+ -sensitive, Ca2+ -dependent hydrolysis, indicating reduced activity of the calcium pump; 3) the passive calcium influx into ATP-depleted red blood cells was slightly accelerated. these abnormalities in Ca2+ binding and transport probably enhanced intracellular Ca2+ concentration, and were observed under both prehypertensive an hypertensive conditions, in 3-week-old and adult SHR respectively. Similar membrane defects in excitable cells may help to explain the pathogenesis of hypertension, since they may increase vascular tone and/or catecholamine release.
