Absence of specific luteinizing hormone releasing hormone receptors in ovine, bovine and porcine ovaries

Crude and membrane-enriched homogenates of unfrozen follicular and luteal tissue from cows, ewes and sows were assayed for the presence of specific luteinizing hormone releasing hormone (LHRH) receptors by one-point saturation analysis using D-Ser-(TBU)6, des-Gly-NH2(10)] LHRH-EA as the labeled and unlabeled ligand. Pituitaries from cows, ewes, sows and rats, and rat ovaries served as positive controls and were assayed with each ovarian tissue assay. Scatchard analysis was used to determine binding affinity of pools of ovarian and pituitary tissue. Specific high-affinity LHRH receptors were found in the pituitaries of cows, ewes, sows and rats and in the rat ovary. In contrast, no specific LHRH binding was detected in follicular or luteal tissue of cows, ewes or sows. Thus, unlike the rat ovary which contains LHRH receptors, ovaries from these domestic species lack specific LHRH receptors.