Repeated electromyostimulation significantly increased sarcolipin and RCAN1 expression in exercised rat legs compared to control legs after the 5th and 10th sessions (p<0.001).
Does repeated transcutaneous electromyostimulation alter sarcolipin and Ca2+ signaling expression in male Sprague-Dawley rats?
Repeated electromyostimulation increases sarcolipin expression in rat skeletal muscle, which correlates with enhanced Ca2+ signaling markers.
p-value: p=<0.001
Calcium ion (Ca 2+ ) acts as a second messenger involved in various adaptations by activating signaling pathways. The expression of Ca 2+ regulators is modified by resistance training. Thus, Ca 2+ signaling may be altered during a period of resistance training. In this study, male Sprague-Dawley rats underwent repeated resistance exercise via transcutaneous electromyostimulation, and the expression of Ca 2+ -related factors was examined 3 h after the 1st, 5th, and 10th exercise sessions. Expression of sarcolipin (SLN) and regulator of calcineurin 1 (RCAN1) was significantly higher in exercised legs than control legs after the 5th ( p < 0.001) and 10th sessions ( p < 0.001). Calcineurin expression showed significant main effects of exercise ( p = 0.009) and session ( p < 0.001). A significant main effect of session was also observed for Ca 2+ /calmodulin-dependent protein kinase II (CaMKII) ( p < 0.001), CaMKII α ( p < 0.046), CaMKII β ( p = 0.002), and CaMKII γ ( p < 0.001). In contrast, expression of sarcoplasmic reticulum Ca 2+ -ATPase (SERCA) did not change with repeated electromyostimulation. Pearson's correlation analysis showed a significant positive correlation between the expression of SLN and RCAN1 ( r = 0.630, p = 0.005) and between SLN and CaMKII γ ( r = 0.471, p = 0.048), as well as a trend for a positive correlation between SLN and CaMKII ( r = 0.463, p = 0.053). These results suggest that repeated sessions of electromyostimulation increase SLN expression, which may in turn contribute to enhanced Ca 2+ signaling after exercise. • Repeated electromyostimulation elevates sarcolipin in rats, peaking by session 5. • Sarcolipin upregulation correlates with RCAN1 and CaMKIIγ, indicating enhanced Ca 2+ signaling. • SERCA protein level remains unchanged across the training sessions.
Okumura et al. (2026) studied Healthy rats. Transcutaneous electromyostimulation vs. Control legs was evaluated on Expression of sarcolipin (SLN) and regulator of calcineurin 1 (RCAN1) (p=<0.001). Repeated electromyostimulation significantly increased sarcolipin and RCAN1 expression in exercised rat legs compared to control legs after the 5th and 10th sessions (p<0.001).