Multiple [3H]-Oxytocin Binding Sites in Rat Myometrial Plasma Membranes

The affinity spectrum method has been used to analyse binding isotherms for [3H]-oxytocin to rat myometrial plasma membranes. Three populations of binding sites with dissociation constants (Kd) of 0.6-1.5 x 10(-9), 0.4-1.0 x 10(-7) and 7 x 10(-6) mol/l were identified and their existence verified by cluster analysis based on similarities between Kd, binding capacity and Hill coefficient. When experimental values were compared to theoretical …