[Calcium binding to the erythrocyte cytoskeleton in spontaneously hypertensive rats]

The paper outlines a new La(3+)-induced mechanism of Ca2+ binding to rat red blood cells. Other compounds elevating intracellular Ca2+ concentrations, such as A-23187, ionomycin, and orthovanadate, and some activators of phosphotransferases (TPA, dibutyryl cAMP) fail to initiate the binding. Inhibitors of calmodulin-dependent processes, such as calmidazolium and trifluoroperazine, diminish La-dependent Ca2+ binding. La(3+)-induced Ca2+ binding is followed by an increased cytoskeleton incorporation rate of 14C metabolites of glucose. The rate of Ca2+ binding and 14C metabolite incorporation was 30% and 80% higher, respectively, but Ca+ binding capacity was increased by 45% in SHR as compared to WKY rats. Due to the fact that La3+ enhances the phosphorylation of proteins with molecular masses of 14, 36, and 58 kD, it is suggested that Ca2+ binding alterations should be determined by changes in phosphorylation and glucose metabolic disturbances in spontaneously hypertensive rats.