Distribution of LH-RH nerve endings in the median eminence of proestrus female rats: fluorescence and peroxidase anti-peroxidase(PAP) immunohistochemistry.

Abstract

The morphological distribution of the nerve terminals containing LH-RH [luteinizing hormone releasing hormone] in the hypothalamus especially in the median eminence of the proestrus female rat was demonstrated by immunohistochemistry. The terminals containing LH-RH were classified into 4 groups on the topographic relationship. LH-RH nerve processes terminated mainly in the infundibular radix within an elliptical zone surrounding the bases of the infundibular recessus. The heaviest concentration of LH-RH terminals immunohistochemically demonstrated lay on each side of the region extending from the dorsal part of tuberoinfundibular sulcus to the lateral part of the external layer of the superior labium of the infundibulum. It was not possible to detect any neuronal soma with immunoreactivity to LH-RH in the hypothalamic gray matter. The distributional patterns of LH-RH, GH-RIH [growth hormone release inhibiting hormone] and monoamine in the median eminence as well as their relationships were briefly discussed.