Modulation of membrane-associated protein synthesis in rat brain cells by the anti-oxidant 2-ethyl-6-methyl-3-oxypyridine

Intraperitoneal injection of different amounts of 6-methyl-2-ethyl-3-oxypyridine (6M2E3OP) to 3- and 18-month-old rats led to significant reduction of translating activity in vitro of membrane-bound polysomes of rat brain cells, but nor of free polysomes. This was more marked in the case of endoplasmic membranes of 18-month-old animals than in these of 3-month-old ones. Separation of polysomes from membranes by Triton X-100 resulted in restoration of template activity to the level of free polysomes. Forty eight hours after intraperitoneal injection of 6M2E3OP to 3- and 18-month-old rats the substance was found, by HPLC, only in endoplasmatic reticulum membranes of brain cells, but not in their cytoplasm. The xenobiotic did not change the age-dependent ratio of free and membrane-bound brain polysomes. At the same time the substance significantly inhibited the mean rate of synthesis of the longest polypeptide chains (MW 28-42,000 daltons) in cells of old animals.