Calmodulin-dependent Ca2+ transport across plasma membranes in primary hypertension.
The rate of calcium transport in the erythrocytes in both forms of primary hypertension [essential hypertension (EH) of humans and spontaneously hypertensive rats (SHR)] and in microsomes of SHR brain were studied. In the erythrocyte membranes subjected to calmodulin depletion by EGTA treatment both the affinity of the Ca-pump for Ca2+ and its maximal activity in primary hypertension did not differ from normotensive controls. The addition of exogenous calmodulin to calmodulin-stripped membranes from erythrocytes of EH or SHR and microsomes of SHR brain resulted in a smaller increase of the Ca-pump activity. It is suggested that the decrease of the rate of calmodulin-dependent calcium transport across the plasma membrane may be a cause for the increased intracellular calcium content found in some tissues in primary hypertension.
D000818:Animals; D002118:Calcium / Q000097:blood*; D002147:Calmodulin / Q000494:pharmacology*; D004910:Erythrocyte Membrane / Q000187:drug effects / Q000378:metabolism*; D006973:Hypertension / Q000097:blood*; D007700:Kinetics; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY
D002147:Calmodulin; D002118:Calcium