[The effect of estradiol on the initiation of phosphoinositide catabolism in rat brain synaptic membranes].

The in vivo effect of estradiol on phosphoinositide catabolism initiation provoked by K(+)-depolarization of rat brain synaptosomal membranes was studied. The decreased yield of diacylglyceride was revealed on the 5th sec of initiation. It was found that estradiol markedly increases the phospholipid content, particularly that of phosphatidylinositol, in synaptosomal membranes but causes a simultaneous decrease of the neutral lipid content. The activity of phosphatidylinositol-specific phospholipase C is significantly decreased thereby. It was concluded that the effect of the steroid hormone on the genome provides for a functional status of membrane structures which slightly impedes the processes mediated by phosphoinositides.