Changes in arterial, mixed venous and intraerythrocytic ion concentrations during prolonged exercise.

Autor: Meyer ND; College of Veterinary Medicine, Washington State University, Washington, USA. ndmeyer@vetmed.wsu.edu, Bayly WM, Sides RH, Wardrop KJ, Slinker BK
Jazyk: angličtina
Zdroj: Equine veterinary journal. Supplement [Equine Vet J Suppl] 2010 Nov (38), pp. 185-90.
DOI: 10.1111/j.2042-3306.2010.00189.x
Abstrakt: Reasons for Performing Study: Prolonged equine exercise can cause hypochloraemic alkalosis and hypokalaemia secondary to the loss of hypertonic sweat. Movement of ions in and out of erythrocytes during exercise may help regulate acid-base balance and changes in plasma ion concentrations. The extent to which this happens during prolonged equine exercise has not been reported.
Objectives: To measure changes in blood gases and major plasma and intraerythrocytic (iRBC) ion concentrations of horses undergoing prolonged submaximal exercise.
Methods: Six horses were trotted at ∼ 30% VO2max on a treadmill for 105 min. Arterial ((a)) and mixed venous ((v)) blood samples were collected every 15 min, and pre- and post exercise. Blood gases and plasma (pl) concentrations of sodium, potassium, chloride and protein were measured and their iRBC concentrations calculated and compared (P < 0.05).
Results: P(a)CO(2) decreased in all horses. pl[Cl(-)]v decreased and [HCO(3)(-)]v increased. Due to the exhalation of CO(2) and chloride shifting, [HCO(3)(-)]a<[HCO(3)(-)]v, pl[Cl(-)]a>pl[Cl(-)]v)and iRBC[Cl(-)]aiRBC[K(+)]v. Conversely, iRBC[Na(+)]aConclusions: Significant arteriovenous differences in iRBC and plasma concentrations of chloride, potassium and sodium reflect the role that movement of ions across erythrocyte cell membranes play in regulating acid-base balance and plasma concentrations of these ions. Exhalation of CO(2) has a major influence on this ion flux.
(© 2010 EVJ Ltd.)
Databáze: MEDLINE
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