Summary
Contractile power, blood flow, O2-uptake. and O2-extraction during isotonic, rhythmic exercise were determined in the isolated canine gastrocnemius muscle during perfusion with blood with hematocrits between 0.21 and 0.81. The results obtained in 36 measurements on nine muscles showed that maximal O2-delivery to the muscle is found at hematocrits between 0.5 and 0.6. Both in the range of hemodilution, and in the range of extreme hemoconcentration, O2-delivery decreases significantly. O2-consumption and contractile power of the muscles are almost unaffected in the hematocrit range between 0.4 and 0.7; beyond and below this hematocrit range both parameters decrease. O2-extraction is virtually constant in the hematocrit range between 0.3 and 0.6, but increases both below and above these hematocrit levels.
It is concluded that due to reduced vasodilatory reserve in working skeletal muscle compared to resting muscle the optimal hematocrit is shifted to higher values.
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Balke, B., Grillo, G. P., Konecci, E. B., Luft, U. C.: Work capacity after blood donation. J. Appl. Physiol. 7, 231–238 (1954)
Bassenge, E., Höfling, B., Restorff, W. v.: Inertial pressure loss in hemodilution. Bibl. Haematol. 41, 140–147 (1975)
Blomqvist, G., Johnson, R. L., Saltin, B.: Pulmonary diffusing capacity limiting human performance at altitude. Acta Physiol. Scand. 76, 284–287 (1969)
Chien, S.: Biophysical behaviour of red cells in suspensions. In: The red blood cell. Surgenor, D. M., (ed.), Vol. 2, pp. 1032–1133. New York, San Francisco, London: Academic Press 1975
Cotter, M., Hudlicka, O., Vrbova, G.: Growth of capillaries during long-term activity in skeletal muscle. Bibl. Anat. 11, 395–398 (1973)
Crowell, J. W., Smith, E. E.: Determinants of the optimal hematocrit. J. Appl. Physiol. 22, 501–504 (1967)
Ekblom, B., Goldbarg, A. N., Gullbring, B.: Response to exercise after blood loss and reinfusion. J. Appl. Physiol. 33, 175–180 (1972)
Fahraeus, R., Lindqvist, T.: The viscosity of the blood in narrow capillary tubes. Am. J. Physiol. 96, 562–568 (1931)
Faulkner, J. A., Kollas, J., Favour, C. B., Buskirk, E. R., Balke, B.: Maximum aerobic capacity and running performance at altitude. J. Appl. Physiol. 24, 685–691 (1968)
Gaehtgens, P., Benner, K. U., Schickendantz, S.: Effect of hemodilution on blood flow, O2-consumption, and performance of skeletal muscle during exercise. Bibl. Haematol. 41, 54–60 (1975)
Gaehtgens, P., Benner, K. U., Schickendantz, S.: Nutritive and non-nutritive blood flow in canine skeletal muscle after partial microembolization. Pfluegers Arch. 361, 183–189 (1976)
Gullbring, B., Holmgren, A., Sjöstrand, T., Strandell, T.: The effect of blood volume variations on the pulse rate in supine and upright positions and during exercise. Acta Physiol. Scand. 50, 62–70 (1960)
Hammersen, F.: The pattern of the terminal vascular bed and the ultrastructure of capillaries in skeletal muscle. In: Oxygen transport in blood and tissue. Lübbers, D. W., Luft, V. C., Thews, G., Witzleb, E. (eds.), p. 184. Stuttgart: Thieme 1968
Hermansen, L., Wachtlova, M.: Capillary density of skeletal muscle in well trained and untrained men. J. Appl. Physiol. 30, 860–863 (1971)
Hint, H.: The pharmacology of dextran and the physiological background for the clinical use of Rheomakrodex and Makrodex. Acta Anaesthesiol. Belg. 19, 119–138 (1968)
Hirche, H., Raff, W. K., Grün, D.: The resistance to blood flow in the gastrocnemius of the dog during sustained and rhythmical isometric and isotonic contractions. Pfluegers Arch. 314, 97–112 (1970)
Horstman, D. H., Gleser, M., Wolfe, D., Tryon, T., Delehunt, J.: Effects of hemoglobin reduction on VO2 max and related hemodynamics in exercising dogs. J. Appl. Physiol. 37, 97–102 (1974)
Hudlicka, O.: Muscle blood flow. Amsterdam: Swets & Zeitlinger 1973
Levy, M. N., Share, L.: The influence of erythrocyte concentration upon the pressure-flow relationship in the dog's hind limb. Circ. Res. 1, 247–255 (1953)
Messmer, K., Sunder-Plassmann, L., Klövekorn, W. P., Holper, K.: Circulatory significance of hemodilution: rheological changes and limitations. Adv. Microcirc. 4, 1–77 (1972)
Messmer, K., Lewis, D. H., Sunder-Plassmann, L., Klövekorn, W. P., Mendler, N., Holper, K.: Acute normovolemic hemodilution. Changes of central hemodynamics and microcirculatory flow in skeletal muscle. Eur. Surg. Res. 4, 55–70 (1972)
Messmer, K., Görnandt, L., Jesch, F., Sinagowitz, E., Sunder-Plassman, L., Kessler, M.: Oxygen transport and tissue oxygenation during hemodilution with dextran. Adv. Exp. Med. Biol. 37B, 669–680 (1973)
Messmer, K., Sunder-Plassman, L., Jesch, F., Görnandt, L., Sinagowitz, E., Kessler, M.: Oxygen supply to the tissues during limited normovolemic hemodilution. Res. Exp. Med. (Berl.) 159, 152–166 (1973)
Murray, J. F., Gold, P., Johnson, B. L.: Systemic oxygen transport in induced normovolemic anemia and polycythemia. Am. J. Physiol. 203, 720–724 (1962)
Murray, J. F., Gold, P., Johnson, B. L.: The circulatory effects of hematocrit variations in normovolemic and hypervolemic dogs. J. Clin. Invest. 42, 1150–1156 (1963)
Murray, J. F., Escobar, E., Rapaport, E.: Effects of blood viscosity on hemodynamic responses in acute normovolemic anemia. Am. J. Physiol. 216, 638–642 (1969)
Race, D., Dedichen, H., Schenk, W. G.: Regional blood flow during dextran-induced normovolemic hemodilution in the dog. J. Thorac. Cardiovasc. Surg. 53, 578–586 (1967)
Restorff, W. v., Höfling, B., Holtz, J., Bassenge, E.: Effect of increased blood fluidity through hemodilution on general circulation at rest and during exercise in dogs. Pfluegers Arch. 357, 25–34 (1975)
Richardson, T. Q., Guyton, A. C.: Effects of polycythemia and anemia on cardiac output and other circulatory factors. Am. J. Physiol. 197, 1167–1170 (1959)
Rowell, L. B.: Human cardiovascular adjustments to exercise and thermal stress. Physiol. Rev. 54, 75–159 (1974)
Saltin, B.: Aerobic and anaerobic work capacity at 2300 meters. Med. Thorac. 24, 205–210 (1967)
Saltin, B., Grover, R. F., Blomqvist, C. G., Hartley, L. H., Johnson, R. L.: Maximal oxygen uptake and cardiac output after 2 weeks at 4,300 m. J. Appl. Physiol. 25, 400–409 (1968)
Smith, E. E., Crowell, J. W.: Influence of hematocrit ratio on survival of unacclimatized dogs at simulated high altitude. Am. J. Physiol. 205, 1172–1174 (1963)
Vatner, S. F., Higgins, C. B., Franklin, D.: Regional circulatory adjustments to moderate and severe chronic anemia in conscious dogs at rest and during exercise. Circ. Res. 30, 731–740 (1972)
Whittacker, S. R. F., Winton, F. R.: Apparent viscosity of blood flowing in the isolated hindlimb of the dog, and its variation with corpuscular concentration. J. Physiol. (Lond.) 78, 339–369 (1933)
Williams, M. H., Goodwin, A. R., Perkins, R., Bocrie, J.: Effect of blood reinjection upon endurance capacity and heart rate. Med. Sci. Sports 5, 181–186 (1973)
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Gaehtgens, P., Kreutz, F. & Albrecht, K.H. Optimal hematocrit for canine skeletal muscle during rhythmic isotonic exercise. Europ. J. Appl. Physiol. 41, 27–39 (1979). https://doi.org/10.1007/BF00424466
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DOI: https://doi.org/10.1007/BF00424466