STIMULATION OF GONADOTROPIN-RELEASING-HORMONE SECRETION BY ACETYL-L-CARNITINE IN HYPOTHALAMIC NEURONS AND GT1 NEURONAL CELLS

Pulsatile gonadotropin-releasing hormone (GnRH) secretion from perifus ed hypothalamic cells and GT1-1 neuronal cells was significantly incre ased after culture in medium containing 100 mu M acetyl-L-carnitine (A LC). This action of ALC was largely due to an increase in the spike am plitude of GnRH release. In addition, the receptor-mediated release of GnRH by N-methyl-D-aspartic acid and endothelin was significantly inc reased in perifused cells cultured in ALC-enriched medium. Stimulatory effects of ALC on basal, high K+- and agonist-induced GnRH release we re also observed during long-term culture of primary hypothalamic neur ons. Similar effects of ALC were evident in cultured GT1-1 cells and w ere accompanied by a significant increase in cell number. These observ ations in normal and transformed GnRH neurons demonstrate that ALC pro motes the growth and secretory activity of neuropeptide-producing cell s of the hypothalamus.