Effects of acute and chronic ethanol administration on thromboxane and prostacyclin levels and release in rat brain cortex

Abstract

The effects of acute (3 g/kg i.p. two jours before sacrifice) and chronic (6% in drinking water and libitum for 15 days) ethanol administration to male rats (200 g body weight) on basal levels and release of TxB 2n2 and 6-keto-PGF 1α in brain cortex were studied. Also the effects of chronic ethanol (30 days) on the fatty acid composition of brain cortical tissue and liver phospholipids were investigated. Acute treatment reduced basal levels of 6-keto-PGF 1α in brain cortical tissue (rats sacrificed by microwave radiation) and decreased the accumulation of 6-keto-PGF 1α in brain cortex after post-decapitation ischemia (PDI). Basal TxB 2 levels were also reduced in brain cortex, but TxB 2 release during PDI was enhanced. Chronic treatment (15 days) induced changes of TxB 2 and 6-ketoPGF 1α levels and release during PDI in brain cortex less pronounced than those observed after acute treatment. The reduced effectiveness of chronic ethanol on brain vasoactive eicosanoids suggest adaptation processes. After chronic treatment (30 days), the fatty acid composition of brain cortex total phospholipids were not significantly modified. Changes of eicosanoid production after ethanol were thus independent from modifications of the fatty acid precursor pool(s). Ethanol-induced changes in the production of vascular eicosanoids in the CNS may be of relevance to the action of the compound on the CNS and may also have implications for the clinic.