IMMUNOHISTOCHEMICAL STUDY ON DISTRIBUTION OF Gn RH-ASSOCIATED PEPTIDE IN THE FOREBRAIN AND HYPOTHALAMUS OF RODENTS / 解剖学报

ABSTRACT

Gonadotropin-releasing hormone(GnRH)prohormone of human and rat consistsof GnRH and GnRH-associated peptide(GAP).In this study,three antisera againstN-terminal,mid-region and C-terminal of GAP,and ABC immunoenzyme methodwere used to observe the GAP neurons in the brains of the rat,mouse and guineapig.The distribution of GAP neurons in these animals was similar.GAP perikaryawere mainly present in the septo-preoptic area,with the largest concentration inthe diagonal band near the organum vasculosum of the lamina terminalis.SomeGAP perikarya were also seen in the brain area near the supraoptic nucleus.GAPfibers were widely present in the forebrain and hypothalamus,and terminated inthe organum vasculosum of lamina terminalis and median eminence.Of 3 GAP antisera,the one against N-terminal gave more immunoreactive elements and moreintense staining.The morphology and distribution of GAP perikarya,fibers andterminals were similar to those of GnRH.These results,combined with other relatedfacts,suggest that there is a common GnRH prohormone in mammals,and itsprocessing products,GAP(or cleavage fragments)and GnRH,are cosecreted intohypophysial portal system to regulate anterior pituitary hormone secretion.