Spontaneous calcium release induced by ethanol in the isolated rat brain microsomes.
Ethanol-induced neurotransmitter release in unstimulated synaptosomes was found to be independent of extrasynaptosomal Ca2+ concentration, indicating a redistribution of intracellular Ca2+. The effects of alcohol on microsomal Ca2+ uptake and release were studied. In vitro addition of 100 mM ethanol had no effect on ATP-dependent Ca2+ accumulation in the microsomes. However, the same amount of ethanol released 25% of total accumulated Ca2+ from the microsomes. Ethanol induced Ca2+ release in a concentration-dependent manner over the range 30 mM-500 mM. The amount of Ca2+ release increased with higher alcohols. The effect of alcohol was temperature-dependent and inhibited at 0 degrees C. These results indicate that the known stimulatory effects of ethanol on resting release of neurotransmitters may be due to the microsomal release of Ca2+.
Shah
J
J
Laboratory of Physiological and Pharmacological Studies, National Institute on Alcohol Abuse and Alcoholism, Rockville, MD 20852.
Pant
H C
HC
D000818:Animals; D001923:Brain Chemistry / Q000187:drug effects*; D002118:Calcium / Q000493:pharmacokinetics*; D000431:Ethanol / Q000494:pharmacology*; D008297:Male; D008861:Microsomes / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D000431:Ethanol; D002118:Calcium