Interaction of vasopressin with human blood platelets: dependency on Mg2+.
Arginine-vasopressin (AVP) in the presence of Mg2+ but not in the absence of bivalent cations led to accumulation of [32P]-phosphatidic acid [( 32P]-PA) in human blood platelets. Mg2+ also enhanced the specific binding of [3H]-AVP to intact platelets. The concentrations of the cation which enabled AVP to cause half maximal rise of [32P]-PA and those inducing half maximal [3H]-AVP-binding were of the same order. It is concluded that the stimulation of phosphatidyl inositide breakdown by AVP in presence of Mg2+ is at least partially due to a Mg2+-induced enhancement of specific AVP-binding to the platelet membranes.
D001127:Arginine Vasopressin / Q000378:metabolism / Q000494:pharmacology; D001792:Blood Platelets / Q000187:drug effects* / Q000378:metabolism; D002462:Cell Membrane / Q000187:drug effects; D006801:Humans; D008274:Magnesium / Q000502:physiology*; D010712:Phosphatidic Acids / Q000378:metabolism; D010761:Phosphorus Radioisotopes; D011485:Protein Binding; D014667:Vasopressins / Q000378:metabolism / Q000494:pharmacology*
D010712:Phosphatidic Acids; D010761:Phosphorus Radioisotopes; D014667:Vasopressins; D001127:Arginine Vasopressin; D008274:Magnesium