DIVALENT CATIONS INCREASE [3H]‐PROSTACYCLIN BINDING TO MEMBRANES OF NEURONAL SOMATIC HYBRID CELLS

Abstract

1 [³H]-prostacyclin binding to membranes of a highly differentiated neuronal somatic hybrid is increased equally in the presence of Ca²⁺, Ba²⁺, Mg²⁺ or Sr²⁺ ions. 2 Analysis of the binding of [³H]-prostacyclin in the presence of low (1 mm) or high (50mm) Mg²⁺ ion concentrations has revealed a cation-dependent increase in ligand receptor affinity (K_d⁻ values = 57.4 nM and 21.9 nM). 3 The increase in [³H]-prostacyclin binding due to divalent cations is not accompanied by an alteration in the maximum binding capacity of the membranes.