Endurance training increases skeletal muscle Na/H+ exchanger1 (NHE1) and Na/HCO3 cotransporter1 (NBC1) gene and protein expressions in rats

Abstract

The purpose of this research was to study the effects of endurance training on the expression of NHE1, NBC1 genes and proteins in rat muscle. Twenty male Wistar rats (n = 20), 4 weeks old and 93.7 ± 10.8 g, were selected and divided into the control and the training groups, randomly. Endurance training was performed at a relatively low speed and duration for 7 weeks in the first week, with durations of 20 m min−1 and 20 min, and gradually reached 30 m min−1 and 35 min in the last week. The NHE1, NBC1 gene and protein expressions were determined by Real-time PCR and Western Blot techniques, respectively. Our results indicated that in the training group, the expressions of NHE1 and NBC1 mRNA in EDL increased respectively, compared with the control group (P < 0.05). There was a significant increase in soleus NHE1 mRNA, but this difference was not significant in Soleus NBC1 mRNA in comparison to the control group (P > 0.05). The protein expressions of NHE1 in Soleus and EDL increased by 32% and 31%, respectively (P < 0.05). The protein expressions of NBC1 in Soleus and EDL were not significant compared to the control group (P > 0.05). The results show that endurance training with moderate intensity and volume could improve the ability of skeletal muscle pH adjustment through the H+ transport pathway independent of lactate. This increase depends on the specificity of the most important transporter and fiber type in pH adjustment.