Specific binding of luteinizing hormone releasing hormone to human luteal tissue

Homogenates of human luteal tissue bound radioiodinated luteinizing hormone releasing hormone agonist. Specific binding was both time- and temperature- dependent. Native LHRH and two LHRH agonists competed for binding, whereas TRH, somatostatin and oxytocin did not, indicating that the binding sites were specific. The apparent Ka values were 2 × 10 7M −1 for both LHRH agonists and 10 6M −1 for native LHRH. This is the first demonstration of specific binding of LHRH to human ovarian tissue. No binding could be detected to ovarian tissue from postmenopausal women.