Opioid-adrenergic-steroid connection in regulation of luteinizing hormone secretion in the rat.

In this article we have attempted first to summarize the current information on the effects of each of the three neuronal systems - gonadal steroid concentrating neurons, catecholamine and opioid producing neurons - on various aspects of luteinizing hormone releasing hormone (LHRH) secretion. The salient features of the new information are: (1) gonadal steroids are capable of raising LHRH levels in the median eminence nerve terminals without changing LH (LHRH) secretion; (2) a chain of temporally related neural events in the preoptic-tuberal pathway precede the preovulatory LH release; (3) catecholamines may provide a permissive environment for appropriate function of LHRH neurons, and (4) the inhibitory influence of endogenous opioid peptides on LH release may be mediated by adrenergic neurons in the preoptic-tuberal pathway. Based on this information we have constructed a conceptual model which attempts to integrate the inputs of these three systems during the episodic basal and cyclic release of LH in the rat.