Immunoreactive LRF neurosecretory pathways in mammals.

Using antisera to synthetic luteinizing hormone-releasing factor (LRF) and antisera labeled with fluorescein isothiocyanate or peroxidase, it was possible in various physiological and experimental conditions to determine the topography of the LRF secretory cells in the guinea pig. The axons of these cells form a preoptico-infundibular LRF pathway, which controls the prehypophyseal gonadotropic secretion, and various "extrahypophyseal pathways". These latter suggest that LRF, in addition to its prehypophysiotropic action, may have a neuromodulator function.