In this study, the effects of (1) asphyxia and (2) asphyxiation followed by resuscitation on brain levels of prostaglandins E₂ and F_2α were evaluated in 2-day-old guinea pigs. Asphyxiation in a nitrogen atmosphere for either 3 min or 3 min 40 s did not alter brain PGF_2α levels but after 3 min 40 s of asphyxia, brain PGE₂ levels were significantly elevated from control values. When asphyxiation was followed by resuscitation with 95% 0₂ and 5% CO₂, brain PGF_2α levels rose significantly while PGE₂ levels were not different from nonasphyxiated control values. Pretreatment of animals with indomethacin lowered brain levels of both prostaglandins below nonasphyxiated control levels and prevented any asphyxiation or resuscitation-induced rise in brain prostaglandin levels. Also, animals which were asphyxiated, resuscitated, and sacrificed 1 day after asphyxiation had brain prostaglandin levels which were not different from levels in nonasphyxiated control animals. These studies demonstrate a significant rise in brain PGF_2α levels following resuscitation from acute total asphyxia. We speculate that the resuscitation-induced rise in brain PGF_2α may contribute to restriction of cerebral blood flow in the postasphyxial period through its action as a vasoconstrictive agent.

No abstract