Biosynthesis of the luteinizing hormone releasing hormone (LH-RH) in the rat hypothalamus.

The biosynthesis of LH-RH was followed and evaluated in the hypothalamus of intact and castrated female rats after the infusion into the 3rd cerebral ventricle of L-3H-Glycine and its incorporation into the synthetized hormone. Incorporation of 3H-Gly into the LH--RH molecule that means biosynthesis of this hormone was found 30 min after the infusion of labeled amino acid. The incorporation rate in castrated animals was 2 times higher than in intact ones. Estradiol-17 beta only slightly depressed the LH--RH biosynthesis rate in castrated animals. Pretreatment with cycloheximide or puromycin decreased biosynthesis rate of the hormone by 50%. On the basis of cycloheximide and puromycin action it is suggested that the ribosomes are involved in the biosynthesis of LH--RH.