Catecholamine metabolism during adaptation to muscular activity

: In rats, an increased O-methylation in the brain, heart, liver, and in the m. gastrocnemius as well as an increased intensity of oxidative desamination in the liver were revealed after muscular training and administration of retabolile. After additional 70-min swimming, in intact rats the MAO activity was raised in the liver, and the intensity of O-methylation - in the muscle and the heart. In rats adapted to muscular training, no increase of O-methylation in the heart or MAO activity in the liver was observed which may be regarded as an adaptive hypometabolic reaction of the organism for a more "ecomonic" usage of the catecholamines. An increase of the catecholamines contents was revealed in adrenals of the rats after training and retabolile administration. The 70-min swimming obviously suppressed the catecholamines synthesis in the rat adrenals. The synthetic activity of the adrenals in trained animals was also decreased, although insignificantly, which resulted from the preliminary adaptation of the organism to muscular activity.