Cardiac adrenergic preponderance due to lack of physical exercise and its pathogenic implications∗

Raab, W.; Silva, P. de Paula E; Marchet, H.; Kimura, Eizen; Starcheska, Y.K.

doi:10.1016/0002-9149(60)90077-1

Cited by 62 publications

(17 citation statements)

References 83 publications

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“…In man, attention has been predominantly directed at the relationship between heart rate and the phases of systole both in groups and in individual subjects. Studies in single subjects have involved the use of exercise (10)(11)(12)(13)(14)(15)(16)(17), drugs (11,18,19), or other maneuvers (15,20,21), to alter heart rate. The resulting changes in the duration of both ejection and systole depend not only on heart rate, but also upon changes in stroke volume and in the inotropic background produced by the interventions.…”

Section: Discussionmentioning

confidence: 99%

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Pressure-flow studies in man. An evaluation of the duration of the phases of systole

Harley¹,

Starmer²,

Greenfield³

1969

J. Clin. Invest.

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A B S TR A C T This study was designed to assess the independent effects of stroke volume and heart rate on the phases of systole and other selected hemodynamic parameters. By means of the pressure gradient technique instantaneous blood pressure and flow were recorded in the ascending aorta at fixed ventricular rates in five patients with complete heart block and in four patients with atrio-ventricular dissociation induced by ventricular pacing. Because of the variable contribution of atrial systole to ventricular filling, a wide range of stroke volumes were observed at each heart rate. The results indicate that the duration of ejection bears a close direct linear relationship to stroke volume while heart rate has only a weak but independent relation. On the other hand, the duration of total systole is related chiefly to the heart rate but stroke volume exerts an important independent effect. In a given patient, both duration of ejection and pulse pressure reflect changes of stroke volume and the product of the duration of ejection and the pulse pressure shows a good correlation with the stroke volume. INTRODUCTIONPrevious studies in man of the relationships between heart rate, stroke volume, and other hemodynamic parameters such as the phases of systole, have been limited by the methodological difficulties encountered in measuring phasic blood flow. The recent development of the pres-

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Section: Discussionmentioning

confidence: 99%

“…It is clear that this period can only be regarded as an index of contractility in terms of the relation to stroke volume and heart rate for any particular beat. Thus, in the past, the explanation of the effect of exercise and drugs on preejection period has met with difficulty (11,12).…”

Section: Discussionmentioning

confidence: 99%

Pressure-flow studies in man. An evaluation of the duration of the phases of systole

Harley¹,

Starmer²,

Greenfield³

1969

J. Clin. Invest.

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“…Apesar de o treinamento físico provocar bradicardia de repouso, tanto no homem [24][25][26] como no animal [27][28][29][30][31] , na presente investigação esse fenômeno não foi verificado. Essa distinção evidencia que o TFE realizado pelos futebolistas não foi direcionado para exercícios de intensidade predominantemente moderada e de longa duração, pois é a partir do exercício realizado com essas características que se verifica diminuição da FC de repouso.…”

Section: Comentários E Discussãounclassified

Efeito do treinamento físico específico nas respostas cardiorrespiratórias e metabólicas em repouso e no exercício máximo em jogadores de futebol profissional

Silva

Romano

Yazbek

et al. 1997

Rev Bras Med Esporte

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ma (196 ± 10 vs. 198 ± 8mmHg). A resposta ventilatória máxima foi significativamente aumentada (129 ± 19 vs. 140 ± 16L.min -1 [p< 0.05]), enquanto a capacidade aeróbia má-xima não foi significativamente modificada (50,0 ± 6,0 vs. 53,0 ± 5,0ml.kg.-1 min -1 ) por esse treinamento. Ao contrário, a capacidade anaeróbia máxima aumentou significativamente (8,3 ± 0,2 vs. 9,8 ± 2,4mmol.L -1 [p< 0,05]). Concluiu-se: 1) o TFE não modificou as respostas de FC e PA no repouso e no exercício máximo; 2) a maior V E no exercício máximo associada a elevada concentração sanguínea de ácido lático demonstraram que o TFE utilizado nesse estudo foi caracterizado por exercícios predominantemente intensos; e 3) o TFE não representou estímulo adequado para aumentar a capacidade aeróbia máxima dos futebolistas. RESUMOO objetivo deste estudo foi analisar as alterações provocadas pelo treinamento físico específico (TFE) nas respostas cardiorrespiratórias e metabólicas de 16 jogadores de futebol profissional, com média de idade de 24,2 ± 3,6 anos. Todos os atletas foram avaliados antes e depois de quinze semanas de um programa de TFE, durante período competitivo. Os futebolistas foram submetidos a teste máximo em esteira rolante, utilizando-se o protocolo de Ellestad 20 . A resposta de freqüência cardíaca (FC) foi registrada por meio de um eletrocardiógrafo de 3 derivações simultâneas e a pressão arterial (PA), por meio de método auscultatório. A ventilação pulmonar (V E ), o consumo de oxigênio (VO 2 ), a produção de dióxido de carbono (VCO 2 ) e a razão de troca respiratória (RER) foram calculados a partir de valores medidos por um sistema espirométrico computadorizado (Beckman) e a capacidade anaeróbia máxima, por meio da concentração sanguínea de ácido lático, utilizando-se analisador automático. O TFE não modificou significativamente a FC máxima (192 ± 8 vs. 186 ± 6bpm) e a PA sistólica máxi-1. Fisiologista do exercício.2. Cardiologista chefe do laboratório de fisiologia.

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“…The unchanged activity of choline acetyltransferase in the ventricular muscle of the trained rat seems to suggest that the prolonged isometric contraction period of the ventricles observed after training [Mellerowicz, 1956;Klepzig, 1955;Raab, Silva, Marchet, Kimura and Starcheska, 1960] might be caused chiefly by sympathetic inhibition as discussed by Herrlich, Raab and Gigee [1960]. It should perhaps also be mentioned that parasympathetic control of the ventricles is questioned [see Higgins, Vatner and Braunwald, 1973].…”

Section: Weightsmentioning

confidence: 99%

Choline Acetyltransferase in the Heart and Salivary Glands of the Rat After Physical Training

Ekström

1974

Exp Physiol

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After physical training of rats for 11-14 weeks both weight of atria and weight of ventricles were higher in relation to body weight than those of untrained controls. The capacity to synthesize acetylcholine, as judged by the activity ofcholine acetyltransferase, was increased in the atria of the trained rats, but the enzyme activity did not change in the ventricles. This result seems to support the concept of a high cholinergic activity as one cause of the low resting heart rate after training.Salivary glands are known to take part in thermo-regulation in rats. After the period of training increased submaxillary gland weight was found in relation to bodyweight, but two other major salivary glands were unchanged. Although the training seems to have caused increased secretory activity of the submaxillary gland, no changes in the activity of choline acetyltransferase were noticed.Increased cholinergic activity is one of the factors which has been suggested as responsible for the low heart rate observed after physical training [Herrlich, Raab and Gigee, 1960;Tipton and Taylor, 1965; Tipton, Barnard and Tharp, 1966]. Choline acetyltransferase is present both in the atria [Tucek, 1964;Ekstr6m, 1970] and ventricles [Ekstr6m, 1970] of the rat's heart. In the present study the effect on the synthesis of acetylcholine in these two parts has been determined after prolonged physical training. Since it is known that the salivary glands of the rat take part in thermoregulation and the rats were found to spread saliva onto their body surfaces after the runuing sessions, choline acetyltransferase activity was estimated also in the parotid and submaxillary glands. METHODSMale rats, initially about 3 months old, of a Sprague-Dawley strain bred at this Institute were exercised in a motor driven rotating drum six to seven times weekly. The speed and running period were slowly increased. At the beginning of the 7th week the rats ran at 1500 m/hr for 1 hr/day. This training program was then continued until the experiment was finished 4 to 7 weeks later. Before and after the training sessions a film of plastic (Nobecutan, Bofors) was sprayed on to the feet of the animals. To prevent the rats from sliding a plate of metal was built into the drum. When the tail or the back was in contact with this plate the rats were electrically stimulated. Some of the rats were conditioned in the respect that the mere touch of the plate caused them to run again, although no electrical stimulation had occurred. However, during the weeks of exercise many rats had to be abandoned. In spite of the electrical stimulation some of them refused to run; this was especially seen in the first weeks of exercise. Some rats got swollen legs or injured their digits.The experimental rats were housed together with their respective control litter mates. Food and water were given ad libitum. Body weights were measured at the start and at the end of the experimental period; at the end the body lengths were also 73

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Cardiac adrenergic preponderance due to lack of physical exercise and its pathogenic implications∗

Cited by 62 publications

References 83 publications

Pressure-flow studies in man. An evaluation of the duration of the phases of systole

Pressure-flow studies in man. An evaluation of the duration of the phases of systole

Efeito do treinamento físico específico nas respostas cardiorrespiratórias e metabólicas em repouso e no exercício máximo em jogadores de futebol profissional

Choline Acetyltransferase in the Heart and Salivary Glands of the Rat After Physical Training

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