Expressão gênica de MTOR, MURF-1 e MAFBX em ratos wistar suplementados com whey proteins por doze semanas

Abstract

Introduction: The whey proteins have long been used by practitioners of physical activities and athletes, especially because they have high nutritional value and present proven link with muscle hypertrophy. Its importance is often overestimated, leading athletes and physical activity individuals to consume very high doses of protein, without the guarantee of additional benefits. Objective: To verify the effect of the supplementation of different doses of Whey Proteins during 12 weeks in the gene expression of MTOR, MURF-1 and MAFBx and in the alteration of the cellular diameter of the gastrocnemius muscle. Methodology: The present study was approved by the Ethics Committee on Animal Use (UFMA protocol no. 23115.014424/2015-54). Experimental design, with 38 male Rattus novergicus Wistar rats aged 60 days and body mass of 250g, were randomly assigned to four groups, one control and three intervention groups, identified by the Whey Proteins supplementation dosage (2, 4 and 6 g/kg/day) for 12 weeks by the gavage procedure three times a day, one hour apart. At the end of 12 weeks of supplementation, a 24-hour fasting period followed by euthanasia over ketamine/xylazine overload (75:10 mg / kg), the right white gastrocnemius muscle was removed and stored in the Rna Latter solution, then it was stored at -80 ° C and subjected to real-time polymerase chain reaction analysis. The left gastrocnemius muscle was intended for histological analysis. Data were then tabulated and analyzed with descriptive and analytical statistics (Shapiro-Wilk (p>0.05), Anova (p<0.05) and Tukey's test post (p<0.05). Results and Discussion: Gene expression of MTOR mRNA had lower statistical significance in the groups of Whey 2, Whey 4 and Whey 6 than in the control group, in the order of 100%, 97% and 96%, respectively. Likewise, the gene expression of MURF-1 mRNA had lower statistical significance in the groups of Whey 2, Whey 4 and Whey 6 than the control group, in the order of 65%, 75% and 84%, respectively. In line, the gene expression MAFBX mRNA had lower statistical significance in the groups Whey 2, Whey 4 and Whey 6 in relation to the control group, in the order of 99%, 97% and 99%, respectively. There was no statistical difference in the cellular area of the gastrocnemius muscle between the groups. Conclusion: Therefore, supplementation of Whey Proteins at doses of 2, 4 and 6 g / kg / day for 12 weeks in sedentary animals was not able to increase the gene expression of MTOR mRNA, however, it was able to reduce the gene expression of MURF -1 mRNA and MAFBX mRNA.