Effect of time of day and physical exercise on inflammatory biomarkers in athletic horses.

Abstract

INTRODUCTION: The present study aimed to investigate the effect of time of day and physical exercise on some inflammatory biomarkers (white blood cell count-WBCs, leukocyte subpopulation CD4&#x202f;+&#x202f;and CD8&#x202f;+&#x202f;cells, total proteins, Interleukins IL-6, IL-1&#x3b2; and Tumor Necrosis Factor TNF&#x3b1;) in trained saddle horses. METHODS: Blood samples were collected from 10 horses before, immediately (following 5&#x202f;min) and 1&#x202f;h after the training session in the morning (am) and afternoon (pm). RESULTS AND DISCUSSION: Statistical analysis showed increasing value of WBCs immediately and 1 h after exercise (<&#x202f;0.01:<&#x202f;0.01) at am compared to rest. Lower CD4 + oncentration was observed immediately and 1 h after exercise (<&#x202f;0.01;<&#x202f;0.01) at pm compared to rest and decreased levels 1-h post-exercise at pm compared to am (<&#x202f;0.001). CD8 + exhibited significant lower value at pm compared to am at each time point (before:<&#x202f;0.01; immediately:<&#x202f;0.01; 1 h after:<&#x202f;0.001). IL-6 showed increasing value post-exercise at pm (<&#x202f;0.01). IL-6 and IL-1&#x3b2; levels were markedly elevated at pm compared to am at each time point (<&#x202f;0.0001;<&#x202f;0.0001;<&#x202f;0.0001). This information is essential for formulating suitable training regimens, considering performance in connection to possible daily risk for infection, illness, and inflammation to which the horse may be vulnerable.