The Effect of Endurance Training on the Intracellular Content of Proteins Related to the Ubiquitin-Proteasome Pathway in the Left Ventricle of Type-2 Diabetic Rats

The Ubiquitin pathway is responsible for muscle atrophy; the Atrogin-1 or muscle atrophy F-box (MAFbx) and the muscle Ring-Finger protein-1 (MuRF1) are the important factors in this pathway. This study aimed to investigate the effect of endurance training on the intracellular content of proteins related to the Ubiquitin-Proteasome pathway in the left ventricular tissue of rats with type-2 diabetes. 

In this experimental study, 18 three-month-old male Sprague-Dawley rats with a mean weight of 270±20 grams were selected. Type-2 diabetes was induced in 12 rats by intraperitoneal injection of streptozotocin and nicotinamide solutions. These rats were randomly divided into two diabetic training and diabetic control groups. A healthy control group (six rats in each group) was also considered. The training group did endurance training four days a week according to the training program for eight weeks. Data were analyzed using one-way ANOVA and Tukey post hoc tests via SPSS software version 23.

MAFbx protein content showed a significant change after eight weeks of endurance training (P=0.0001); Tukey's post hoc test showed that this significant change was between pairs of the diabetic training compared with diabetic control (decrease) groups (P=0.0001)  and diabetic training compared with the healthy control (increase) groups (P=0.004). MuRF1 protein content showed a significant decrease (P=0.0001); This reduction was significant between pairs of diabetic training compared with diabetic control groups (P=0.0001).

Endurance training can prevent atrophy and lead to proper left ventricular function by reducing the content of MAFbx and MuRF1 proteins in the heart of diabetic rats.