Modulation of circulating purines and pyrimidines by physical exercise in the horse

Abstract

This study was designed to examine the influence of sub-maximal exercise on purine and pyrimidine catabolism in horses. Ten horses were initially trained for 12 weeks at the end of which they underwent a standardized exercise test (SET); venous blood samples were taken at rest, 5 and 30 min after the SET. Six untrained healthy horses, from which a blood withdrawal was taken at rest, were used as the control group. Samples were analyzed by HPLC for the simultaneous determination of uric acid, uridine, β-pseudouridine and creatinine in plasma. Glucose and lactate were measured in blood. Trained horses had basal uridine levels significantly lower than sedentary horses. The SET caused significant increase in plasma uric acid, uridine, β-pseudouridine and creatinine. Following the SET, a significant negative correlation was found between plasma uridine and glucose, whilst a significant positive correlation was observed between plasma uric acid and creatinine. These results indicate that increase in energy demand during exercise in the horse causes not only the degradation of purine but also of pyrimidine compounds, the latter possibly exerting a control on glucose uptake as also demonstrated in human beings.

Untargeted Metabolomics Profiling Reveals Exercise Intensity-Dependent Alterations in Thoroughbred Racehorses’ Plasma after Routine Conditioning Sessions

“…Changes in metabolites downstream of purine metabolism (inosine, xanthine, urate, allantoin) align with previous studies that reported similar changes in purine metabolites after exercise and attributed them to adenosine triphosphate (ATP) consumption during exercise. , Given the high energy demand associated with high-intensity exercise, these findings are expected after racing. , None of the above-mentioned studies have reported modifications in pyrimidine metabolites. Beyond their role in energy metabolism, both purine and pyrimidine metabolites may serve as regulatory molecules in response to exercise …”

“…Beyond their role in energy metabolism, both purine and pyrimidine metabolites may serve as regulatory molecules in response to exercise. 56 Tricarboxylic Acid Cycle Intermediates. The elevated levels of oxoglutarate and isocitrate, key intermediates in the TCA cycle, following high-intensity exercise, suggest the activation of this metabolic pathway.…”

“…Beyond their role in energy metabolism, both purine and pyrimidine metabolites may serve as regulatory molecules in response to exercise. 56 …”

The Role of Intestinal Microbial Metabolites in the Immunity of Equine Animals Infected With Horse Botflies

“…The upregulated genes were associated with the pathways of UTP to UDP (3.6.1.5), UDP to UMP (3.6.1.5, 3.6.1.6), UMP to uridine In mammals, when mitochondrial activity is unable to support energy demand, muscles produce ATP through the adenylate kinase reaction in the purine metabolism. The product of purine metabolism is uric acid (82). There are differences in purine metabolism in different species, which cause gout and renal stones in humans, but the effects of which on horses are not known (83).…”

Body Temperature and Plasma Nitric Oxide Metabolites in Response to Standardized Exercise Test in the Athletic Horse

“…Horses were not involved in an exercise or riding curriculum of any kind, prior to or during the study. Horses were accustomed to individual housing and work on the training mill and treadmill during an adaptation period of 12 weeks, reaching a light-medium fitness level according to previous exercise protocols [10][11]. The daily training during the adaptation period consisted of the following sequence: 5 min walk (approximate speed = 0.8 m/s); 10 min trot M A N U S C R I P T…”