The hypothalamo-infundibular growth hormone-releasing hormone (GH-RH) system of the rat.
Two to 10 days after complete unilateral surgical isolation of the medial basal hypothalamus (MBH) or 3 months following neonatal monosodium glutamate (MSG) treatment, the presence of growth hormone-releasing hormone (GH-RH) immunoreactive neuronal structures was studied in rats using vibratome sections and GH-RH immunocytochemistry. Neonatal MSG treatment resulted in a dramatic decrease of GH-RH immunoreactivity in the median eminence (ME), but not complete disappearance as reported earlier. Unilateral complete deafferentation of the MBH caused only a slight decrease in GH-RH immunostaining in the posterior regions of the ipsilateral median eminence (ME). At this level GH-RH accumulation was observed in scattered transected fibers lateral to the cut, outside of the MBH. Our findings indicate that the arcuate nucleus is the major source of GH-RH immunoreactive structures in the ME. Although, however, in very small numbers, the existence of other sources of GH-RH terminals cannot be excluded.
D000818:Animals; D000831:Animals, Newborn; D001111:Arcuate Nucleus of Hypothalamus / Q000378:metabolism; D013007:Growth Hormone-Releasing Hormone / Q000378:metabolism*; D007031:Hypothalamus / Q000378:metabolism*; D007033:Hypothalamus, Middle / Q000378:metabolism; D007124:Immunoenzyme Techniques; D008297:Male; D008473:Median Eminence / Q000378:metabolism; D051381:Rats; D012970:Sodium Glutamate / Q000494:pharmacology
D013007:Growth Hormone-Releasing Hormone; D012970:Sodium Glutamate