Influence of protein deficient diet, vitamin B[sub]2[/sub] supplementation and physical training on serum composition of polyunsaturated fatty acids (PUFAs) in rats.

[b]Introduction[/b]. Prolonged shortages of protein in the diet significantly alter the composition and content of polyunsaturated fatty acids (PUFA) in tissues and body fluids. One of nutritional factors which may reduce negative effects of protein malnutrition might be vitamin B[sub]2[/sub] due to its influence on lipids metabolism. [b]Objective. [/b]The aim of the study was to investigate the influence of low protein (LP) diet enriched with vitamin B[sub]2[/sub] on the content and composition of PUFA in the blood serum of rats treated with dosed physical exercise. [b]Materials and method. [/b]The experiment was carried out for 3 months on 72 growing male Wistar rats divided into 5 groups. Animals were fed ad libitum on a diet with an energy value of 350 kcal/100 g, in which 4.5% of the energy was provided by protein. In the control diet, 20% of the energy was provided by protein. Two groups were fed the diet enriched with vitamin B2. The two groups of tested animals were trained for 5 days a week. [b]Results.[/b] LP diet caused a decrease in α-linolenic acid (ALA) after 30 days, and a decrease in docosahexaenoic acid (DHA) after 60 days of experiment, compared with rats fed the control diet. After 60 and 90 days of the experiment, a significant decrease was noted in arachidonic acid (AA) in serum of trained rats, compared with sedentary rats fed the LP diet. Physical activity increased LA (mainly on day 30), EPA (on day 90) and reduced AA content (on day 90) in serum of rats fed the LP diet. B2 supplementation in the trained LP group did not change the EPA and AA dependence; however, there was a decrease in LA content in comparison to the non-supplemented trained group. [b]Conclusions. [/b] Results of this study suggest that all investigated factors (protein deficiency, physical exercise and supplementation of vitamin B2) have significant impact on PUFA composition of serum in rats.