Changes in serum cortisol and some innate immunity parameters after exhaustive exercise in male dogs.

Abstract

The aim of the present study was to investigate the influence of exhaustive exercise on some innate immunity parameters and cortisol levels. Twelve male, mongrel dogs were divided into an experimental group, submitted to prolonged, strenuous exercise with exhaustion as the end-point, and a control group without any exposure to exercise. Serum cortisol levels were measured before exer-cise (BE), right after (0 h) and on 2nd hour and 4th hour after exercise. The neutrophil function (phagocytosis, phagocytic index, hydrogen peroxide production-H2O2) and classical pathway of com-plement activation (CPCA) were measured as followеd: BE, right after exercise and on 2, 4, 24, 48, 72 h, and 7, 14 day after exercise. In experimental animals cortisol decreased on hour 4 after exercise (P<0.05), compared to BE level, and on hour 2, compared to controls (P<0.05). Percentage of H2O2 producing neutrophils in experimental animals dropped significantly on hour 4 and day 7 after exer-cise (P<0.05), compared to BE level and on hour 4 (P<0.01) vs control group. Percentage of phago-cytising neutrophils decreased slightly on hour 48 (P<0.05), compared to BE level. Phagocytic index and CPCA had an insignificant increase after exercise. Inappropriate changes in cortisol levels could indicate inadequate adaptive response to exercise. Overtraining could make animals more susceptible to infection.

Keywords

• complement system
• cortisol
• dog
• exercise
• phagocytosis