Effect of acute ethanol on beta-endorphin secretion from rat fetal hypothalamic neurons in primary cultures.
To characterize the effect of ethanol on the hypothalamic beta-endorphin-containing neurons, rat fetal hypothalamic neurons were maintained in primary culture, and the secretion of beta-endorphin (beta-EP) was determined after ethanol challenges. Constant exposure to ethanol at doses of 6-50 mM produced a dose-dependent increase in basal secretion of beta-EP from these cultured cells. These doses of ethanol did not produce any significant effect on cell viability, DNA or protein content. The stimulated secretion of beta-EP following constant ethanol exposure is short-lasting. However, intermittent ethanol exposures maintained the ethanol stimulatory action on beta-EP secretion for a longer time. The magnitude of the beta-EP response to 50 mM ethanol is similar to that of the beta-EP response to 56 mM of potassium. Ethanol-stimulated beta-EP secretion required extracellular calcium and was blocked by a calcium channel blocker; a sodium channel blocker did not affect ethanol-stimulated secretion. These results suggest that the neuron culture system is a useful model for studying the cellular mechanisms involved in the ethanol-regulated hypothalamic opioid secretion.
Sarkar
D K
DK
Department of Veterinary and Comparative Anatomy, Washington State University, Pullman 99164-6520.
Minami
S
S
D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004622:Embryo, Mammalian; D000431:Ethanol / Q000494:pharmacology*; D007033:Hypothalamus, Middle / Q000502:physiology*; D007700:Kinetics; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D013779:Tetrodotoxin / Q000494:pharmacology; D014700:Verapamil / Q000494:pharmacology; D001615:beta-Endorphin / Q000378:metabolism*
D000431:Ethanol; D013779:Tetrodotoxin; D001615:beta-Endorphin; D014700:Verapamil; D002118:Calcium