[Variations in prostaglandin E content in the arterial blood and cerebrospinal fluid under conditions of hypo- and hypercapnia].

A marked increase in the prostaglandin E (PGE) content in the cerebrospinal fluid (CSF) and the arterial blood of cats was observed under conditions of 3-minute hypocapnia. During 30-minute hypocapnia a restoration of the initial PGE level was seen. The PGE content in CSF increased while in the arterial blood it decreased comparatively to the control under conditions of 3-minute hypercapnia. In 30-minute hypercapnia the PGE amount in the CSF and the blood dropped in comparison with 3-minute hypercapnia being below the basal level in the blood. It is suggested that in hypocapnia PGE should limit its constrictive effect on the cerebral vessels while under conditions of hypercapnia they are to promote the realization of the cerebral vessel reaction to CO2.