Quantitative analysis of acid–base balance in show jumpers before and after exercise

• Published in: Research in veterinary science Vol. 68; no. 2; pp. 103 - 108
• Main Authors: AGUILERA-TEJERO, E., ESTEPA, J.C., LÓPEZ, I., BAS, S., MAYER-VALOR, R., RODRÍGUEZ, M.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-04-2000
• Subjects: Acid-Base Equilibrium - physiology; Animals; Calcium - blood; Horses - physiology; Lactic Acid - blood; Physical Conditioning, Animal - physiology; Potassium - blood; Protons; Sodium - blood; Sports
• ISSN: 0034-5288; 1532-2661
• DOI: 10.1053/rvsc.1999.0341

The acid–base status of venous blood was studied in 17 show jumpers before and after exercise using both a traditional and a quantitative approach. Partial pressure of carbon dioxide (PCO2), pH, haemoglobin, and plasma concentrations of sodium (Na+), chloride (Cl–), potasium (K+), ionized calcium (Ca2+), total proteins, albumin, lactate and phosphorus were measured in jugular venous blood samples obtained before and immediately after finishing a show jumping competition. Bicarbonate, anion gap and globulin concentration were calculated from the measured parameters. ‘Quantitative analysis’ of acid–base balance was performed utilising values for three independent variables: PCO2, strong ion difference [SID = (Na++ K++ Ca2+) – (Cl–+ Lact)] and total concentration of weak acids [AT= Alb (1¶23 pH – 6¶31) + Pi (0¶309 pH – 0¶469) 10/30¶97]; plasma concentrations of hydrogen ion ([H+]) were also calculated from these variables using Stewart’s equation. No significant changes in blood pH were detected after the show jumping competition. Exercise resulted in a significant increase in lactate, Na+, K+, haemoglobin, total proteins, albumin, globulin and anion gap, and a decrease in bicarbonate, Cl–and Ca2+. PCO2decreased after exercise while SID and ATincreased. A significant correlation between measured and calculated [H+] was found both before and after exercise. However, individual [H+] values were not accurately predicted from Stewart’s equation. In conclusion, even though pH did not change, significant modifications in the acid–base balance of horses have been found after a show jumping competition. In addition, quantitative analysis has been shown to provide an adequate interpretation of acid–base status in show jumpers before and after exercise.