Effect of prolonged physical training on the catecholamine levels of the heart and the adrenals of the rat.

Abstract

AbstractThe effect of prolonged physical training on the noradrenaline content of the heart and the catecholaniine content of the adrenal glands was studied on rats. the trained rats showed a moderate but highly significant cardiac hypertrophy (heart weight of controls: 1.32±0.01, trained rats: 1.41 ±0.01, heart ratio (g heart weight/100 g b.w.) of controls: 0.29 ± 0.003, trained rats: 0.34 ± 0.003). There was no difference in cardiac noradrenaline concentration between trained and untrained rats (controls: 0.69±0.04 μg/g, trained rats: 0.73±0.03 μg/g). There was a highly significant increase in adrenaline content of the adrenal glands espressed as μg adrenaline/kg b.w. (Controls 93±5 μg/kg, trained rats: 122 ± 5 μg/kg). It is concluded that prolonged physical training does not lower the amounts of synipatlictic trans mitter of the heart. It is further suggested that an increased adrenaline content in the adrenal glands might be a manifestation of an adaptation to the increased demands upon the rardio vascular system in rats subjccted to prolonged physical training.