The effect of exercise on the clearance of infused acetate in the horse

This study was designed to determine if exercise affected the clearance of intravenously infused acetate in the horse. Plasma acetate concentrations were measured in 4 conditioned horses during submaximal exercise and at rest following an infusion of sodium acetate (2.5 mmol/kg body weight [BW]). The effects of acetate infusion were compared with an equivolume infusion amount of 0.9% NaCl. Plasma glucose, lactate, free fatty acid, glycerol, triglyceride, and β-hydroxybutyrate concentrations were also analyzed. After infusion, plasma acetate concentrations decreased more rapidly during exercise (t1/2: 4.5 minutes) than at rest (t1/2: 11.7 minutes; P < .05). Although plasma acetate clearance was accelerated by exercise, there did not appear to be an increased conversion of acetate to either β-hydroxybutyrate or triglyceride, as concentrations of these variables did not increase following acetate infusion in exercising horses. Sodium acetate infusion caused a decrease in plasma free fatty acid concentrations (P < .05) at rest and during exercise. A similar pattern occurred for glycerol concentrations (P < .05). Glucose concentrations increased in response to acetate infusion during exercise (P < .05). The results suggest that acetate may be useful as an energy source during submaximal exercise.