Ischemia‐Induced Alterations in Lipid Metabolism of the Gerbil Cerebral Cortex: I. Changes in Free Fatty Acid Liberation

Abstract: Does the impaired lipid metabolism during nonlethal transient ischemia truly recover within a few hours after recirculation? In an attempt to answer this question, we first investigated the time course of the changes in the amount and composition of free fatty acids (FFAs) accumulated during 5‐min ischemia and after various postischemic recirculation durations (3 min, 1 h, 24 h, 3 days, and 6 days) in the gerbil cerebral cortex. Then those of FFAs liberated in response to the second 5‐min ischemia at various recirculation intervals (3 min, 1 h, 3 days, and 6 days) following the initial one were also measured to evaluate the changes in the cellular response. The former study disclosed that the FFA levels transiently returned to the control levels at 1‐h recirculation, increased again a few days after the onset of recirculation, followed by the final return to the control levels after 6‐day recirculation. The latter study disclosed that the cellular response to the second ischemia was quite different from that to the initial one even after 6‐day recirculation, suggesting that membrane lipid metabolism had not yet been recovered even at such a late period. We discuss the significance of the alterations in lipid metabolism.