ALPHA-GLYCERYLPHOSPHORYLCHOLINE ADMINISTRATION INCREASES THE GH RESPONSES TO GHRH OF YOUNG AND ELDERLY SUBJECTS

Growth hormone (GH) secretion is decreased during aging in humans and in rodents. This decrease may be due to increased hypothalamic somatos tatin release, which is inhibited by cholinergic agonists, or to decre ased secretion of GHRH. Alphaglyceryl-phosphorylcholine (alpha-GFC) is a putative acetylcholine precursor used in the treatment of cognitive disorders in the elderly. In order to learn what effect alpha-GFC had on GH secretion, GH-release hormone (GHRH) was given to young and old human volunteers, with or without the addition of alpha-GFC. GH secre tion was greater in the younger subjects than in the old individuals, and both groups had a greater GH response to the GHRH + alpha-GFC than to GHRH alone. The potentiating effect of alpha-GFC on GH secretion w as more pronounced in the elderly subjects. These findings confirm the observation that aged individuals respond less well to GHRH than youn ger subjects, and provides further evidcence that increased cholinergi c tone enhances GH release.