Plasma aldosterone concentration and renal sodium excretion are altered during the first days of training.

摘要: Summary The purpose of the present study was to determine whether training-induced hypervolemic response seen in horse is associated with aldosterone-mediated renal mechanisms affecting sodium conservation during first days training. Five healthy, Standardbred mares (weight 450–500 kg, age 4–8 years) that were unfit, but accustomed running on treadmill, used test hypothesis repeated submaximal exercise would alter plasma aldosterone (ALDO) concentration and excretion electrolytes horses within 3 The experiment consisted a 2 week housing equilibration period followed by 1 control day training (30 min/day at 60% VO2max). During control, ALDO fluid electrolyte losses measured for 24 h separate days. Renal function (urine volume [UV], Na+, K+ CI- [UNA+V, UK+V, UClV], clearance Na+ [CNa+], [CK+] Cl− [CCl-], creatinine [CCr], osmotic substances [Cosm], solute-free water [FWC], fractional Cl−) an additional consecutive period. There no differences (P>0.05) any variable Plasma increased (+18.7%, P<0.05) after training, there significant changes osmolality, concentrations or CCr. Training caused decreases (P<0.05) UV (-30%), UNA+V (-73%), (-55%) UCl-V (-70%). also Cosm through CNa+ (-60%), CK+ CCl- (-66%). Interestingly, FWC (+30%, P<0.05), whereas, (-59%), (-48%) (-60%). substantial elevations both pre-exercise (967%, postexercise (+3013%, suggesting increase basal levels responsiveness acute exercise. Together, these observations suggest tubular contribute early However, it concluded appear be only part mechanism conserving intake as well gastrointestinal balance.