Chronic ethanol inhibits rat hippocampal "stimulus-secretion" coupling mechanism for 5-hydroxytryptamine in vitro.
Effects of ethanol on serotonergic neurotransmission were investigated in crude mitochondrial fraction (P2 fraction) from rat brain hippocampus and hypothalamus. The [14C]5-HT preloaded P2 fraction was exposed to 45 mM KCl to induce 5-hydroxytryptamine release in vitro. Ethanol in vitro did not produce any significant inhibition of [14C]5-HT release until its concentration was greater than 100 mM. The K+-evoked 45Ca uptake of hippocampal P2 fraction was unaffected by 100 mM. However, 200 mM ethanol inhibited approximately 63% of K+-evoked 45Ca uptake. Chronic ethanol (10 g/kg/day) for 6 days inhibited [14C]5-HT release from hippocampus whereas it did not affect [14C]5-HT release from hypothalamus. Results indicate that chronic ethanol treatment may decrease serotonergic neurotransmission in selective brain regions. The reduction in 5-hydroxytryptamine release was the result of inhibition in "stimulus-secretion" coupling mechanism.
D000437:Alcoholism / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000378:metabolism; D000431:Ethanol / Q000633:toxicity*; D006624:Hippocampus / Q000187:drug effects* / Q000378:metabolism; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism; D066298:In Vitro Techniques; D008297:Male; D009433:Neural Inhibition / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000378:metabolism*; D013997:Time Factors
D012701:Serotonin; D000431:Ethanol; D002118:Calcium