Effect of Physical Training on Cardiac Catecholamine Concentrations

Schryver, Christian De; Herdt, P. de; Lammerant, J

doi:10.1038/214907b0

Cited by 29 publications

(5 citation statements)

References 4 publications

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“…Lactic dehydrogenase activity has also been found to be increased (8). Myocardial catecholamine levels are diminished in hearts of conditioned rats (9).…”

Section: Introductionmentioning

confidence: 88%

The effect of physical training upon the mechanical and metabolic performance of the rat heart

Penpargkul¹,

Scheuer²

1970

J. Clin. Invest.

112

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A B S T R A C T The dynamic and metabolic performance of rats conditioned by a swimming program (CH) and hearts of sedentary rats (SH) was studied in an isolated working rat heart apparatus. Heart rate, filling pressure, and afterload were controlled or kept constant, and heart weights were comparable in both groups.When compared with SH, CH had increased cardiac output and cardiac work. Atrial pacing at more rapid rates caused greater differences in these functions, and left ventricular pressure and maximal rate of pressure rise (dp/dt) became higher in CH than in SH. Atrial pacing was associated in CH with increased oxygen consumption but in SH by increased lactate and pyruvate production.When atrial filling pressure was elevated in order to perform ventricular function curves, CH showed greater dynamic responses than SH. There were also greater increments in oxygen consumption, and the ratio of aerobic to anaerobic energy production was also higher in CH.The mechanism of increasing oxygen consumption during stress in CH was mainly by improved coronary flow. In SH coronary flow did not change, but extraction of oxygen from the perfusing fluid increased.The results indicate that in physically trained rats the function of the heart as a pump is improved. These hearts have greater aerobic and mechanical reserve than hearts of sedentary animals. These effects appear to be at least partially due to improved mechanisms of oxygen delivery.

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“…Lactic dehydrogenase activity has also been found to be increased (8). Myocardial catecholamine levels are diminished in hearts of conditioned rats (9).…”

Section: Introductionmentioning

confidence: 88%

The effect of physical training upon the mechanical and metabolic performance of the rat heart

Penpargkul¹,

Scheuer²

1970

J. Clin. Invest.

112

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“…Intense exercise causes an enlargement of the heart combined with chronic bradycardia in rats (Hatai 1915, cf. Tipton 1965, Leon andBloor 1968). In recent studies (De Schryver et al 1967 a pronounced decrease in the concentration and the total amount of cardiac catecholamines in trained rats has been reported, and it has been suggested that this decrease oi sympathetic transmitter might in part explain the bradycardia of the athletic heart. The effect of training upon the size of the heart seems to be dependent upon the intensity of the training program (Leon and Bloor 1968).…”

mentioning

confidence: 98%

“…The effect of training upon the size of the heart seems to be dependent upon the intensity of the training program (Leon and Bloor 1968). In the studies in which a decrease in catecholamines of the hearts or trained animals were determined (De Schryver et al 1967 the training load was comparatively low. In the present investigation a comparatively intense training program was used.…”

mentioning

confidence: 99%

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

ÖStman

Sjöstrand

1971

Acta Physiologica Scandinavica

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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.

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“…Mechanisms responsible for reduced sensitivity to isoproterenol in animals trained under a higher workload program (HI) are unclear. Receptor binding did not appear to playa role, since there were no exercise training-related effects on either B max or K d • One possibility is that endurance training may depress myocardial catecholamine stores (27). Another possibility is that training-or obesityinduced alterations in muscarinic receptor density/sensitivity may affect responses to isoproterenol because of its interaction with the~-adrenergi c signal transduction pathway via G i .…”

Section: Discussionmentioning

confidence: 97%

A Comparison of Two Exercise Training Programs on Cardiac Responsiveness to β-Stimulation in Obesity

Carroll

Thaden

Wright

2005

Exp Biol Med (Maywood)

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We demonstrated previously that exercise training did not restore normal cardiac beta-adrenergic responsiveness in obese rabbits. This study tested the hypothesis that an increased training volume was required to attenuate obesity-related reductions in isolated heart responsiveness to isoproterenol. Female New Zealand White rabbits were divided into lean control, lean exercise-trained, obese control, and obese exercise-trained groups. For the exercise-trained groups, total treadmill work over 12 weeks was increased 27% when compared with lean and obese animals trained with lower total training volume. After 12 weeks, Langendorff isolated hearts were used to study developed pressure, +dP/dt(max), and -dP/dt(max) responses to isoproterenol (10(-9) - 3 x 10(-7) M). Concentration-response data were fit to a sigmoidal function using a four-parameter logistic equation. Controls were compared with animals trained under the low- and high-training volume programs using one-way analysis of variance and Tukey's post-hoc test; separate analyses were conducted for lean and obese rabbits. In both lean and obese groups trained under the high-training volume program, EC50 values for +dP/day(tmax) and -dP/dt(max) were higher compared with same-weight controls and animals trained under the low-training volume program, indicating that contractility and relaxation responsiveness to isoproterenol was reduced by the higher training volume. Therefore, these data indicate that increased training volume failed to attenuate obesity-related decrements in isolated heart responsiveness to beta-adrenergic stimulation and caused reduced sensitivity to isoproterenol in both lean and obese animals.

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Effect of Physical Training on Cardiac Catecholamine Concentrations

Cited by 29 publications

References 4 publications

The effect of physical training upon the mechanical and metabolic performance of the rat heart

The effect of physical training upon the mechanical and metabolic performance of the rat heart

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

A Comparison of Two Exercise Training Programs on Cardiac Responsiveness to β-Stimulation in Obesity

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