Hypothyroidism (Hypo) causes muscle atrophy by reducing the synthesis and increasing protein degradation. Due to side effects and inadequate clinical effectiveness of current drugs for treatment of Hypo and its complications, researchers have attempted to study the effects of non- pharmacological interventions such as exercise and diet. The purpose of this study was to investigate the alterations of Bax and Bcl-2 expression in skeletal muscle of rats with Hypo following moderate-intensity continuous training (MICT) and ascorbic acid administration.
In this experimental study, 30 male Wistar rats (weight 200-220 gr) were randomly divided into five groups, include: control, Hypo, Hypo+MICT, Hypo+supplement and Hypo+MICT+supplement. In order to induce the Hypo, Propylthiouracil (6 mg/kg) was used daily by gavage for eight weeks, followed by the implementation of exercise and dietary interventions. The MICT protocol consisted of 40-min running on treadmill running at a speed of 10-25 m/min, five days a week for eight weeks. The supplement groups received 100 mg/kg ascorbic acid daily through gavage during the intervention. After the interventions, rats were sacrificed and gene expression of Bax and Bcl-2 in the soleus muscle were measured by Real Time-PCR method.
In the Hypo compared to other groups, Bax expression increased and Bcl-2 and the of Bax/Bcl-2 decreased significantly (all; p<0.0001). Bax expression in Hypo+MICT, Hypo+supplement and Hypo+MICT+supplement compared to the control increased significantly (all; p<0.0001), Bcl-2 expression in the Hypo+MICT+supplement compared to the control (p=0.027), and in Hypo+MICT (p=0.002) and Hypo+supplement (p=0.0001) compared to Hypo+MICT+supplement decreased significantly. Also, Bax/Bcl-2 ratio increased significantly in Hypo+MICT and Hypo+supplement compared to the control and Hypo+MICT+supplement (all; p<0.002).
These findings indicated that simultaneous use of MICT and ascorbic acid administration with possitive alterations in apoptosis markers, is an effective approach to preventing from Hypo- induced muscle atrophy.