Effect of Prolonged Physical Training on the Catecholamine Levels of the Heart and the Adrenals of the Rat

Abstract

The 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.

Exercise and dietary cholesterol alter rat myocardial capillary ultrastructure

“…In this study exercise elevated HM/BM ratios to a greater extent in the rats fed a normal diet, suggesting that cholesterol feeding may have an interactive effect with exercise. These findings agree, in part, with those of Ostman and Sjostrand (1971), who reported higher HM/BM ratios in their exercise-trained rats following a strenuous program of swimming. Since exercise training appeared to have no real effect on heart mass, results suggest that the HM/BM ratio differences were due to more dramatic fluctuations in body mass.…”

“…Animal studies that used an exercise program consisting of swimming to exhaustion reported increases in heart-mass-to-body-mass (HM/BM) ratios (Ostman and Sjostrand 1971). Exercise also improves the vasculature of the myocardium, as evidenced by greater capillary-to-myocyte ratios and increased capillary densities in exercise-trained rats (Anversa et al 1982(Anversa et al , 1983.…”

A single bout of exercise increases hippocampalBdnf: influence of chronic exercise and noradrenaline

“…-adrenergic receptor activation and normal LC-noradrenergic signaling are necessary for exercise-induced increases in Bdnf transcription Ivy et al 2003). Although exercise training is associated with an increased capacity for catecholamine release (ÖStman & Sjöstrand 1971;Schmidt et al 2008;Stallknecht et al 1990), a history of physical activity is associated with a reduced stress response (Dishman et al 1997(Dishman et al , 1998(Dishman et al , 2000Greenwood et al 2003). For example, the norepinephrine release/depletion in the LC and hippocampus induced by treadmill or immobilization stress is reduced by 6 weeks of treadmill training (Dishman et al 2000).…”

“…). Although exercise training is associated with an increased capacity for catecholamine release (ÖStman & Sjöstrand ; Schmidt et al . ; Stallknecht et al .…”

Commentary on the reduced urinary noradrenaline excretion following cold stress and exercise in physically trained rats

“…l . One group ffruinrtl ruts l/) was subjected to daily exercise by running on a rolling mat as described by Ostman & Sjostrand (1971). The speed was 25 m/min and the period of running was gradually increased from 15 midday to 2 h/day (see Fig.…”