[Changes in kinetics of deaminated biogenic amines in spontaneous hypertension]

Rate of serotonin and benzylamine deamination was increased in liver tissue of rats with spontaneous hypertension. The increase was due to elevation in Vmax value for monoamine oxidases of the A and B types as compared with the corresponding values of control animals. The Vmax value was increased in kidney of hypertensive animals for MAO of the B type (benzylamine as a substrate). At the same time, Km for MAO of the B type was increased in liver tissue, while Km for MAO of the A type was decreased in brain of hypertensive animals. Titration of the MAO active sites exhibited their increased concentration in the B type MAO in liver mitochondria of experimental animals. The data obtained suggest an important role of alterations in the MAO catalytic activity in pathogenesis of spontaneous hypertension.