On the adrenergic mechanism of cerebrovascular resistance regulation.

It has been found out experimentally that there is a decrease in the pressor action of noradrenaline on cerebral vessels during repeated injections, which is probably due to the increased concentration of endogenic prostaglandins in response to noradrenaline administration. During inhibition of prostaglandin biosynthesis we have observed reverse action -- increase in noradrenaline pressor action and sympathetic effect on cerebral vessels. The hypothetic scheme of prostaglandin participation in adrenergic regulation of cerebrovascular tone is presented.