Effects of exercise on erythrocytes in normal and splenectomised Thoroughbred horses

Abstract

SummaryChanges in erythrocyte quality during exercise were determined in 3 control (Group cC) and 3 splenectomised (Group S) 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 Ilevel. 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 Grotup 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.

Horse spleen segmentation technique as large animal model of preclinical trials

“…The analysis of studies in horses showing the changes in the cardiovascular system caused by total splenectomy corroborates the maintenance of part of the component whenever possible (Persson and Bergsten 1975, Davis and Manohar 1988, Hanzawa et al 1995, Wagner et al 1995.…”

“…Anatomical investigations into the angioarchitecture of parenchymatous organs will support partial resections which will be able to be performed in less vascularized areas in an easier manner (Christo and Di Dio 1997). Partial splenectomy in horses has not been reported (Wilson and Constantinescu 1999), although the effects of splenectomy in horses are well documented (Persson and Bergsten 1975, Davis and Manohar 1988, Hanzawa et al 1995, Wagner et al 1995, including the immune response to a disease caused by babesia, a blood protozoa (Dennig and Brocklesby 1965, Simpson et al 1980, De Waal et al 1988, Guimarães et al 1997. Saving spleen procedures are justifiable, depending on the type and extent of splenic injury (Schwartz et al 1974).…”

Analysis of acid–base balance as well as hematological and biochemical parameters in horses of combined driving discipline

“…According to Hanzawa et al (1995), a decrease in MCV and MCHC level usually accompanies light exercise. Greater physical effort in turn causes an increase in the level of these parameters.…”

Abnormalities of the erythron

“…37,75,[185][186][187][188] The decrease in haptoglobin concentrations observed after exercise is consistent with intravascular hemolysis, since the role of this protein is to bind the free hemoglobin in the plasma in order to form a complex, which is then quickly removed by the reticuloendothelial system, allowing the recycling of iron and globin. 37,75,[185][186][187][188] The decrease in haptoglobin concentrations observed after exercise is consistent with intravascular hemolysis, since the role of this protein is to bind the free hemoglobin in the plasma in order to form a complex, which is then quickly removed by the reticuloendothelial system, allowing the recycling of iron and globin.…”