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 microM 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.
Krsmanovic
L Z
LZ
Endocrinology and Reproduction Research Branch, National Institute of Child Health and Human Development, NIH, Bethesda, MD 20892.
Virmani
M A
MA
Stojilkovic
S S
SS
Catt
K J
KJ
D000108:Acetylcarnitine / Q000494:pharmacology*; D000818:Animals; D002478:Cells, Cultured; D016232:Endothelins / Q000494:pharmacology; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism*; D007031:Hypothalamus / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D051379:Mice; D016202:N-Methylaspartate / Q000494:pharmacology; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*
D016232:Endothelins; D007987:Gonadotropin-Releasing Hormone; D016202:N-Methylaspartate; D000108:Acetylcarnitine