MODIFICATION OF INOSITOL 1,4,5-TRISPHOSPHATE CONCENTRATION OF HUMAN ERYTHROCYTES UNDER IN-VIVO PHYSIOLOGICAL CONDITIONS

The concentration of inositol 1,4,5-trisphosphate (InsP(3)) in erythro cytes from volunteers hers been found to modify following strenuous ph ysical exercise. The basal value wets almost regained within some 75 m in after the completion of the effort. The concurrent variations of pH and blood lactate have also been evaluated. Our results represent,to our knowledge, the first evidence of in vivo induced intraerythrocyte InsP(3) modification They reinforce the idea of the participation of i ts precursor phosphatidylinositol 4,5-bisphosphate (PtdIns4,5-P-2) in red bood cell shape regulation by contributing to the interactions bet ween membrane cmd cytoskeleton components.