Changes in selected biochemical constituents of blood collected from horses participating in a 50-mile endurance ride
Deldar, A.; Fregin, F.G.; Bloom, J.C.; Davanipour, Z.
American Journal of Veterinary Research 43(12): 2239-2243
1982
ISSN/ISBN: 0002-9645 PMID: 7165172 Document Number: 193785
Blood samples were collected from 13 horses before, during and at the end of the ride, as well as 1 h and 16 h after the completion of the ride. Decreases were observed in serum concentrations of chloride, potassium, and calcium. An increase in the serum concentration of phosphorous was also observed. The mean concentrations of chloride and calcium remained reduced in the 16-hour postride sample. A small, but significant, increase in sodium and decrease in glucose concentrations were observed in the midride sample. Although midride samples did not show a significant change in blood pyruvate concentration, a significant increase was observed at the end of the ride. Haematocrit and the total protein concentration increased. The horses showed increases in concentrations of free fatty acids, serum enzymes and lactate during the ride. The elevated values of creatine kinase and lactice dehydrogenase decreased, while the aspartate aminotransferase values remained increased long after completion of the ride. The lactate and free fatty acids, which rose significantly during the ride, decreased to approximately pre-ride values by 16 hours after the ride. It is concluded that the changes in serum electrolytes, enzymes, and blood metabolites reflect the sweating, muscle damage, and increased dependence on anaerobic glycolysis and lipid mobilization.