SEASONAL VARIATIONS IN WORKING CAPACITY AND SERUM LACTATE CONCENTRATION IN LABORATORY RATS

Abstract

The available evidence on seasonal changes in work capacity and anaerobic metabolism is very heterogeneous. Animal studies contribute to better understanding of adaptive reactions of the body to various influences and can serve as a basis for the development of physiotherapeutic, pharmacological and other methods to increase adaptive capabilities of the human body to hard working conditions and environmental situations. The aim was to study the characteristics of the five-days working capacity dynamics serum lactate concentration in laboratory rats across seasons. Methods. Eighty male Wistar rats (220-250g) comprised the sample. Measurements were taken in the middle of each season. The working capacity of animals until complete fatigue was assessed in a swimming test at the same time of a day. Results. Working capacity in rats in the swimming test had the highest values in the summer (75.4 s) and in the spring (78 s), while it was the lowest in the autumn (47.8 s). The highest concentrations of lactate we, on the contrary, observed in the in the autumn. Conclusions. Our results suggest that the working capacity in rats is the best in the spring and in the summer, worse in the winter and the worst in the autumn. One may speculate that the genetically determined seasonal pattern of metabolic processes in the skeletal muscle of rats may determines seasonality in their working capacity.