Incorporation of labelled N-acylethanolamine (NAE) into rat brain regions in vivo and adaptive properties of saturated NAE under x-ray irradiation

Abstract

Regional distribution of exogenous N-palmitoylethanolamine in the rat brain was investigated in the study. Possible protective and adaptive effect of N-stearoylethanolamine under 2 Gy whole-body X-irradiation and changes of brain lipid composition were also studied. It was found that after per os administration to rats N-([9,10-3H]-palmitoyl)-ethanolamine was primarily accumulated in hypothalamus, pituitary and adrenal glands and the label amount in brain was 0.95% of the oral dose. Quantities of palmitic acid in total brain phospholipids and plasmalogen form of phosphatidylcholine were increased; free cholesterol and diacyl form of phosphatidylcholine were decreased in 2 weeks after irradiation. 11-OH-corticosteroid level in the blood of exposed rats was decreased in comparison with control animals. N-stearoylethanolamine pre-treatment prevented from increasing the plasmalogen form of phosphatidylcholine and decreasing its diacyl form and restored 11-OH-corticosteroid level in the blood of irradiated rats. Recovering of brain free cholesterol level was observed when N-stearoylethanolamine was post-treated. So, the accumulation of N-([9,10-3H]-palmitoyl)ethanolamine in brain indicates its penetration through blood-brain barrier and suggests the possible role of saturated N-acylethanolamines in brain functioning, particularly, in stress response regulation of the organism by hypothalamus-pituitary-adrenal system. N-stearoylethanolamine treatment of irradiated rats causes protective effect concerning the of irradiation induced changes in the brain lipid composition and in 11-OH-corticosteroid level and modifies phospholipid fatty acid composition.