RESUMO
Effects of acute hypobaric hypoxia (1:30 hrs. at 190-200 mm Hg) on the autolytic changes in lipids of the gray and white substance of the brain were evaluated in an experiment with white rats. Total lipids (TL) in the autolysing segments of the brain of rats sacrificed immediately following the end of hypoxia were noticed to undulate downward starting from minute 10 of incubation, whereas in the gray substance an insignificant TL loss occurred no earlier than in 4 hrs. with return to baseline values by the end of the observation (in 24 hrs.). Hypobaric hypoxia materially reduces phospholipids (PL) in these sections of the brain typically following 24 hrs. of autolysis with concomitant buildup of diglycerides (DG) and free fatty acids (FFA), and triglycerides (TG) in the white substance. There was also evidence of cholesterol (Ch) reduction both in the gray and white substances paralleled by buildup of cholesterol ethers (ChE) in the gray substance. However, after 24-hr incubation in the autolysing brain structures the total cholesterol displayed a strong trend upward. It is presumed that pre-exposure to hypobaric hypoxia enhances not only the hydrolytic PL degradation in the course of autolysis but also activates the transacylation-type rearrangements within the PL-DG-TG and PL-Ch-ChE in the white and gray substance of rat's brain.
