Monoamine oxidase activity in the brain during adaptation to cold and simultaneous exposure to cold and hyperbaric oxygenation

: One--day cold exposure decreases the monoamine oxidase type A activity by 52--54% (serotonin and noradrenaline substrates); the monoamine oxidase type B activity by 14%. Three--day cold exposure leaves the monoamine oxidase type B activity unchanged and decreases the monoamine oxidase type A activity by 29--32%; the enzyme of the latter type acquires the ability for deamination of glucosamine, putrescine and GABA. Under cold adaptation (45 days, 2 degrees C) the monoamine oxidase type A activity remains reduced as on the 3rd day, the type B activity decreases by 19%; enzyme substrate specificity does not change at all. Preliminary cold adaptation prevents alteration of the monoamine oxidase substrate specificity under hyperbaric oxygenation.