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

Pulsatile gonadotropin-releasing hormone (GnRH) secretion from perifused hypothalamic cells and GT1-1 neuronal cells was significantly increased after culture in medium containing 100 mu M acetyl-L-carnitine (ALC). This action of ALC was largely due to an increase in the spike amplitude of GnRH release. In addition, the receptor-mediated release of GnRH by N-methyl-D-aspartic acid and endothelin was significantly increased in perifused cells cultured in ALC-enriched medium. Stimulatory effects of ALC on basal, high K+- and agonist-induced GnRH release were also observed during long-term culture of primary hypothalamic neurons. Similar effects of ALC were evident in cultured GT1-1 cells and were accompanied by a significant increase in cell number. These observations in normal and transformed GnRH neurons demonstrate that ALC promotes the growth and secretory activity of neuropeptide-producing cells of the hypothalamus.