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Effects of exercise on erythrocytes in normal and splenectomised Thoroughbred horses
Author(s) -
HANZAWA K.,
KUBO K.,
KAl M.,
HIRAGA A.,
WATANABE S.
Publication year - 1995
Publication title -
equine veterinary journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.82
H-Index - 87
eISSN - 2042-3306
pISSN - 0425-1644
DOI - 10.1111/j.2042-3306.1995.tb04969.x
Subject(s) - horse , incremental exercise , haemolysis , medicine , erythrocyte fragility , erythrocyte deformability , red blood cell , treadmill , zoology , endocrinology , biology , immunology , hemolysis , blood pressure , heart rate , paleontology
Summary Changes in erythrocyte quality during exercise were determined in 3 control ( Group C ) and 3 splenectomised ( Group 5 ) horses that performed an incremental exercise test on a treadmill until the point of fatigue. Venous blood samples were drawn before the exercise test and immediately after warming‐up and incremental exercise test. Incremental exercise increased erythrocyte count and haemoglobin concentration by 46 and 37% respectively in control horses and by 15 and 17% respectively in Group S animals. Packed cell volume (PCV) increased by 48% in controls but there was no change in Group S animals. Warming‐up decreased mean cell volume (MCV), mean cell Hb (MCH) and mean cell Hb concentration (MCHC) by 9, 19 and 7% in control horses. Incremental exercise restored MCV and MCHC but MCH remained lower than the resting level. In Group S horses, warming‐up and incremental exercise decreased MCV by 6 and 9% respectively, did not change MCH, but increased MCHC by 4 and 15% respectively. Incremental exercise increased erythrocyte density (ED) in Group C but not in Group S horses. Osmotic fragility of erythrocytes measured as the red cell haemolysis rates in 0.56% NaCl (HL) were significantly higher in Group C than in Group S horses regardless of exercise. Warming‐up decreased HL by 7% in Group C vs 19% in Group S horses, but exercise increased HL by 26% in Group C vs 38% in Group S horses. These results suggest that: 1) exercise causes shrinking of erythrocytes; 2) erythrocyte indices are dependent on the intensity of the exercise; 3) release of erythrocytes from the spleen is associated with an increase in osmotic fragility; and 4) exercise changes osmotic fragility regardless of the release of erythrocytes from the spleen into circulation.