Potassium homeostasis during and following exhaustive submaximal static handgrip contractions.

The aim of the present study was to follow local potassium homeostasis during and after exhaustive contractions. Eight subjects performed static handgrip with their right forearm at 10%, 25% and 40% maximal voluntary contraction. Blood flow (venous occlusion plethysmography) and the venous effluent plasma potassium concentration were followed during the contractions and during a 60-min recovery period. Electromyography was registered during exercise (frequency analysis). With all three protocols the blood flow increased significantly during the contractions and the same was true of the effluent plasma potassium concentrations. In the recovery period blood flow and the venous effluent plasma potassium concentration returned to base values within 30 min following 40% maximal voluntary contraction while following 10% and 25% maximal voluntary contraction, venous effluent plasma potassium concentration was still significantly below resting values one hour after the exercise had ceased, indicating a long-lasting uptake of potassium from the blood into the muscles. In line with this a significant potassium deficit was still seen after 1 hour of recovery following 10% and 25% maximal voluntary contraction. It is concluded that the recovery of potassium homeostasis following prolonged low-intensity contractions is a slow process. This may be due to either sequestration of potassium in other tissues with a subsequent slow release and/or insufficient sodium/potassium pump activation. The contraction induced potassium loss may play a major role in muscle performance since it may impair mechanical force production, and it is hypothesized that this may be the origin of low-frequency fatigue.

[1]  F Benfenati,et al.  Quantitative autoradiography of central neurotransmitter receptors: methodological and statistical aspects with special reference to computer-assisted image analysis. , 1986, Acta physiologica Scandinavica.

[2]  R. DeFronzo,et al.  Extrarenal potassium homeostasis. , 1981, The American journal of physiology.

[3]  M. Civan,et al.  Intracellular activities of sodium and potassium. , 1978, The American journal of physiology.

[4]  R. J. Whitney,et al.  The measurement of volume changes in human limbs , 1953, The Journal of physiology.

[5]  G Sjøgaard,et al.  Muscle energy metabolism and electrolyte shifts during low-level prolonged static contraction in man. , 1988, Acta physiologica Scandinavica.

[6]  H. Sjöholm,et al.  Quantitative estimation of anaerobic and oxidative energy metabolism and contraction characteristics in intact human skeletal muscle in response to electrical stimulation. , 1983, Clinical physiology.

[7]  G Sjøgaard,et al.  Water and electrolyte fluxes during exercise and their relation to muscle fatigue. , 1986, Acta physiologica Scandinavica. Supplementum.

[8]  H. Barcroft,et al.  The blood flow through muscle during sustained contraction , 1939, The Journal of physiology.

[9]  S. Skinner,et al.  The circulation in forearm skin and muscle during adrenaline infusions. , 1962, The Australian journal of experimental biology and medical science.

[10]  P. W. Humphreys,et al.  The blood flow through active and inactive muscles of the forearm during sustained hand‐grip contractions , 1963, The Journal of physiology.

[11]  I Petersén,et al.  Dynamic spectrum analysis of myo-potentials and with special reference to muscle fatigue. , 1968, Electromyography.

[12]  H. Christensen,et al.  Quantitative surface EMG during sustained and intermittent submaximal contractions. , 1988, Electroencephalography and clinical neurophysiology.

[13]  P A Merton,et al.  Fatigue of long duration in human skeletal muscle after exercise. , 1977, The Journal of physiology.

[14]  P. Åstrand,et al.  Disposal of lactate during and after strenuous exercise in humans. , 1986, Journal of applied physiology.

[15]  T. Clausen Regulation of active Na+-K+ transport in skeletal muscle. , 1986, Physiological reviews.

[16]  K. Hagbarth,et al.  Multiunit neural responses to strong finger pulp vibration. I. Relationship to age. , 1990, Acta physiologica Scandinavica.

[17]  G Sjøgaard,et al.  Exercise-induced muscle fatigue: the significance of potassium. , 1990, Acta physiologica Scandinavica. Supplementum.

[18]  D. R. Coles,et al.  The source of blood samples withdrawn from deep forearm veins via catheters passed upstream from the median cubital vein , 1958, The Journal of physiology.

[19]  A. McComas,et al.  Increased sodium pump activity following repetitive stimulation of rat soleus muscles. , 1989, The Journal of physiology.

[20]  G. Sjøgaard,et al.  Beta 2-adrenergic stimulation does not prevent potassium loss from exercising quadriceps muscle. , 1990, The American journal of physiology.

[21]  H Kramer,et al.  Changes in mechanical and bioelectrical muscular activity and in heart rate due to sustained voluntary isometric contractions and time required for recovery. Part I: Contractions at constant level of bioelectrical activity. , 1979, Electromyography and clinical neurophysiology.

[22]  I Petersén,et al.  Conduction velocity in ischemic muscle: effect on EMG frequency spectrum. , 1970, The American journal of physiology.

[23]  A. Holmgren,et al.  Spectrophotometric Measurement of Oxygen Saturation of blood in the Determination of Cardiac output. A Comparison with the van slyke Method , 1959 .

[24]  Muscle metabolites with exhaustive static exercise of different duration. , 1972, Acta physiologica Scandinavica.

[25]  L. Rowell,et al.  Potassium, lactate, and water fluxes in human quadriceps muscle during static contractions. , 1981, Circulation research.

[26]  B Bigland-Ritchie,et al.  Motor drive and metabolic responses during repeated submaximal contractions in humans. , 1988, Journal of applied physiology.