Hemodynamic Response to Normovolemic Polycythemia at Rest and during Exercise in Dogs

Very little is known about the influence of polycythemia on oxygen transport during exercise. We studied chronically instrumented dogs trained to run on a treadmill before and after their hematocrit had been increased by isolvolemic exchange transfusion with packed red blood cells. With normovolemic polycythemia, cardiac output fell in a linear fashion as hematocrit was increased to 65%, but these changes were balanced by an increasing oxygen content resulting in constant systemic oxygen transport. Oxgen consumption was unchanged both at rest and during exercise after induction of polycythemia. To investigate the effect of polycythemia on oxygen transport further, we measured both mixed venous Po2 and lactate. Mixed venous Po2 increased and lactate remained unchanged both at rest and in exercising polycythemic dogs. Thus, we conclude that, in conscious animals, systemic oxygen transport is well preserved with increasing hematocrit to at least 65%.

[1]  P.,et al.  Recommended methods for radioisotope red cell survival studies , 2005, Blut.

[2]  M. H. Williams,et al.  The effect of induced erythrocythemia upon 5-mile treadmill run time. , 1981, Medicine and science in sports and exercise.

[3]  R. Weiskopf,et al.  Work capacity during 3-wk sojourn at 4,300 m: effects of relative polycythemia. , 1980, Journal of applied physiology: respiratory, environmental and exercise physiology.

[4]  H. Myrvold,et al.  The effect of polycythemia on blood flow in working and non-working skeletal muscle. , 1980, Acta physiologica Scandinavica.

[5]  N. Gledhill,et al.  Effect of induced erythrocythemia on aerobic work capacity. , 1980, Journal of applied physiology: respiratory, environmental and exercise physiology.

[6]  J. Weil,et al.  Adverse Effects of Normovolemic Polycythemia and Hypoxia onHemodynamics in the Dog , 1978, Circulation research.

[7]  M. H. Williams,et al.  The effect of blood infusion upon endurance capacity and ratings of perceived exertion. , 1978, Medicine and science in sports.

[8]  T. Videman,et al.  Effect of blood removal and autotransfusion on heart rate response to a submaximal workload. , 1977, The Journal of sports medicine and physical fitness.

[9]  J I Hoffman,et al.  Blood flow measurements with radionuclide-labeled particles. , 1977, Progress in cardiovascular diseases.

[10]  J. Mitchell,et al.  Blood flow to respiratory, cardiac, and limb muscles in dogs during graded exercise. , 1976, The American journal of physiology.

[11]  P. Åstrand,et al.  Central circulation during exercise after venesection and reinfusion of red blood cells. , 1976, Journal of applied physiology.

[12]  C. Higgins,et al.  Role of the spleen in the peripheral vascular response to severe exercise in untethered dogs. , 1974, Cardiovascular research.

[13]  D. Ullyot,et al.  Measurement of cardiac output with and organ trapping of radioactive microspheres. , 1973, Journal of applied physiology.

[14]  L. Horwitz,et al.  Role of the Frank‐Starling Mechanism In Exercise , 1972, Circulation research.

[15]  B. Ekblom,et al.  Response to exercise after blood loss and reinfusion. , 1972, Journal of applied physiology.

[16]  J I Hoffman,et al.  Some sources of error in measuring regional blood flow with radioactive microspheres. , 1971, Journal of applied physiology.

[17]  S. White,et al.  A comparison of blood viscosity measured in vitro and in a vascular bed. , 1970, Acta physiologica Scandinavica.

[18]  E. Rapaport,et al.  Ventricular Function Curves in the Exercising Dog , 1969, Circulation research.

[19]  T. Regan,et al.  Late circulatory adjustments to acute normovolemic polycythemia. , 1966, The American journal of physiology.

[20]  H. Stegall,et al.  Muscle Pumping in the Dependent Leg , 1966 .

[21]  J. Patterson,et al.  MECHANISM OF CIRCULATORY RESPONSES TO SYSTEMIC HYPOXIA IN THE ANESTHETIZED DOG. , 1965, The American journal of physiology.

[22]  A. B. Weisse,et al.  HEMODYNAMIC EFFECTS OF NORMOVOLEMIC POLYCYTHEMIA IN DOGS AT REST AND DURING EXERCISE. , 1964, The American journal of physiology.

[23]  R. Conn.  Clinical Chemistry: Principles and Technics , 1964 .

[24]  J. Murray,et al.  The circulatory effects of hematocrit variations in normovolemic and hypervolemic dogs. , 1963, The Journal of clinical investigation.

[25]  J. Murray,et al.  Systemic oxygen transport in induced normovolemic anemia and polycythemia. , 1965, The American journal of physiology.

[26]  A. C. Guyton,et al.  Effect of Hematocrit on Venous Return , 1961, Circulation research.

[27]  J. H. Torrie,et al.  Principles and procedures of statistics: McGraw-Hill Book Company, Inc. New York Toronto London. , 1960 .

[28]  A. Guyton,et al.  Effects of polycythemia and anemia on cardiac output and other circulatory factors , 1959 .

[29]  M. N. Levy,et al.  The Influence of Erythrocyte Concentration upon the Pressure‐Flow Relationships in the Dog's Hind Limb , 1953, Circulation research.

[30]  F. R. Winton,et al.  The apparent viscosity of blood flowing in the isolated hindlimb of the dog, and its variation with corpuscular concentration , 1933, The Journal of physiology.

[31]  J. Barcroft,et al.  The effects of exercise on the vascular conditions in the spleen and the colon , 1929, The Journal of physiology.