Interaction of Vasopressin with Human Blood Platelets: Dependency on Mg²⁺

Summary

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.

Key words

Blood platelets of man - Arginine-vasopressin - Phos-phoinositide turnover: dependence on Mg²⁺ - Magnesium ions - Vasopressin binding: dependence on Mg²⁺

• References

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