[Effect of n-palmitoylethanolamine on energy-dependent transport of Ca2+ in intracellular structures of myometrium and their phospholipid composition].

N-palmitoylethanolamine (NPE) was studied for its effect on the systems of energy-dependent transport of Ca2+ in the intracell structures (mitochondria, endoplasmic reticulum) of permeabilized cells of smooth muscles of the rat uterus as well as on the lipid composition of myocytes. NPE in concentration of 10(-5) M partially (by 30-50%) inhibited energy-dependent accumulation of Ca2+ in endoplasmic reticulum and mitochondria of myometrium cells permeabilized by means of treatment of myocytes suspension by digitonin (0.1 mg/ml). NPE modifies the lipid composition of permeabilized myocytes when determining the increase of the amount of inorganic phosphorus of total phospholipids by 57.3% at the expense of considerable accumulation of phosphatidylcholine, phosphatidylethanolamine and sphingomyelin. It is supposed that the effect of NPE on the systems of energy-dependent transport of Ca2+ is achieved through the modification of phospholipid composition of a cell, while modulating effect of NPE on the active transmembrane transfer of Ca2+ in the intracellular structure can be an important link in the general mechanism of the effect of this compound on Ca2+ metabolism in myometrium and on Ca(2+)-depended control of the contracting function of the uterus.