Calorimetric monitoring of the effect of endurance training and testosterone treatment on rat serum denaturation transition

Abstract

Differential scanning calorimetry (DSC) was applied to evaluate whether endurance training and/or testosterone treatment affect thermal behavior of rat serum. Thirty-six adolescent male Wistar rats were divided into six groups: three untrained and three trained groups, receiving weekly 0, 8, or 80 mg kgBM -1 of testosterone enanthate (TE) each. Total testosterone was significantly higher in both groups treated with the higher TE dose. The rats’ body mass and the levels of serum glucose, uric acid, and free fatty acids were additionally determined. The effect of TE treatment was clearly visible in DSC curves for sedentary rats and much less for trained rats. The differences between averaged endothermic denaturation transitions of serum from sedentary and physically active untreated groups were within an experimental error. A statistically significant increase of the width of peak at its half height and the ratio of excess heat capacity at 75 C and in the temperature of peak maximum (Cp75/Cpmax) were observed due to TE treatment. The same two parameters were significantly lower for physically active rats. Significantly lower values of the enthalpy of serum denaturation (DH) and the first moment of the transition with respect to the temperature axis (M1) were observed for endurance-trained than for sedentary rats.