Gastric emptying, intestinal absorption of electrolytes and exercise performance in electrolyte‐supplemented horses

Abstract

Horses lose considerably more electrolytes through sweating during prolonged exercise than can be readily replaced through feeds. The present study tested an oral electrolyte supplement (ES) designed to replace sweat electrolyte losses. We measured gastric emptying of 3 litres of ES (using gamma imaging of (99)Tc-sulfide colloid), the absorption of Na(+) and K(+) from the gastrointestinal tract using (24)Na(+) and (42)K(+), and the distribution of these ions in the body by measuring radioactivity within plasma and sweat during exercise. Three litres of ES emptied from the stomach as fast as water, with a half-time of 47 min, and appeared in plasma by 10 min after administration (n = 4 horses). Peak values of plasma (24)Na(+) and (42)K(+) radioactivity occurred at 20-40 min, and a more rapid disappearance of K(+) radioactivity from plasma was indicative of movement of K(+) into cells (n = 3 horses). In a randomized crossover experiment (n = 4 horses), 1 h after administration of placebo (water), 1 or 3 litres of ES containing (24)Na(+), horses exercised on a treadmill at 30% of peak oxygen uptake until voluntary fatigue. The (24)Na(+) appeared in sweat at 10 min of exercise, and when horses received 3 litres of ES the duration to voluntary fatigue was increased in all horses by 33 ± 10%. It is concluded that an oral ES designed to replace sweat ion losses was rapidly emptied from the gastrointestinal tract, rapidly absorbed in the upper intestinal tract and rapidly distributed within the body. The ES clearly served as a reservoir to replace sweat ion losses during exercise, and administration of ES prior to exercise resulted in increased duration of submaximal exercise.

Reduced high intensity training distance had no effect on VLa4 but attenuated heart rate response in 2-3-year-old Standardbred horses

“…When horses were at rest, measurement of blood volume were performed in December 2011as 2-year-olds using Evans blue dye dilution as described previously [ 27 ] and a hematocrit value obtained from the last V La4 sample (V La4 test performed the same day). Echocardiograms were recorded using ultrasound d and a 1.7-3 mHz probe in January as 2-year-olds, December as 2-year-olds and December as 3-year-olds.…”

Ad libitum intake of hydroelectrolytes and energy replenishers in horses submitted to marcha training

“…Hydroelectrolyte solutions used for electrolyte replacement in equine athletes should contain adequate amounts of the major electrolytes lost through sweating, and a source of energy which can be glucose, dextrose, or maltodextrin (Lindinger & Ecker, 2013). In Brazil, the commercial products available are pastes containing electrolytes and carbohydrates.…”

Renal protective effects of induction of haem oxygenase‐1 combined with increased adiponectin on the glomerular vascular endothelial growth factor–nitric oxide axis in obese rats

“…The haem oxygenase‐1 (HO‐1)–adiponectin axis (Lindinger & Ecker, ) has recently attracted interest for its possible role in protection of the cardiovascular and renal systems (Li et al . ; Chen et al .…”