Effects of cerebral ischemia and reperfusion on prostanoid accumulation in unanesthetized and pentobarbital-treated...

Cerebral ischemia was induced in unanesthetized gerbils using bilateral carotid artery ligations. The effects of 20 min of global ischemia on the concentrations of prostaglandin F2 alpha (PGF2 alpha), PGE2, 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha), and thromboxane B2 were determined after 0-24 h of reperfusion. Ischemia had little effect on eicosanoid production, but significant increases were observed by 5 min of reperfusion, with maximal levels reached by 15 min of reperfusion. PGF2 alpha was the most concentrated prostaglandin in postischemic brain, whereas PGE2 was most concentrated in control cerebra. Pretreatment with anesthetic doses of pentobarbital supported increased accumulation of PGF2 alpha in postischemic cerebra, increased accumulation of 6-keto-PGF1 alpha during the ischemic episode, and decreased accumulation of PGE2 at 120 min of reperfusion. It appears that the protective effects of barbiturate anesthesia are not expressed by the reduced accumulation of the above eicosanoids.