Effect of alpha-tocopherol on the production of malondialdehyde in rat tissue homogenates after hypobaric exposure.

Alpha-tocopherol content and production of malondialdehyde (MDA) was measured in liver, kidney, heart, lung, brain and skeletal muscle homogenates of control and hypoxic rats (following a 2-h-exposure to 200 mm Hg): the samples were incubated at 37 degrees C in air for 1 h. MDA production showed no relation with the content of alpha-tocopherol in control and hypoxic rats. In control animals, the lowest MDA level was found in lungs: it was several fold lower than in other tissues. After hypobaric exposure, a marked increase in MDA level could be observed in lungs only. No marked changes in alpha-tocopherol concentration could be observed in any of the tissues tested. A single i.p. injection of 25 and 50 mg/alpha-tocopherol acetate/kg body mass, 2 hours prior to the exposure produced organ-specific accumulation of alpha-tocopherol. Both doses of alpha-tocopherol resulted in a reduced (by about 40%) production of MDA in lung homogenates. The addition of alpha-tocopherol (750 nmol/g wet tissue mass) to homogenates from control and hypoxic rats prior to the incubation resulted in a marked inhibition of MDA production in all tissues (49-70%).