[Catecholamine levels in rats during cooling and administration of succinic acid derivatives].

The effect of tonibral and another succinate derivative (IOH-13) on catecholamine level in the rat organs was studied after 48 hours of acute exposure to low temperature (-15 degrees C). The injection of these drugs prevented the decrease in catecholamine concentration in the heart and stabilized its content in the muscles. The higher survival of rats injected IOH-13, as compared to those injected tonibral, correlated with the higher catecholamine level in the heart muscle. It is suggested that adaptive increase of biogenic amines in the heart muscle plays an important role in the protective effect of these drugs during severe cooling.