PRKG1 and endothelial dysfunction: Chen et al. (2015) found that SCU exerted endothelium-dependent relaxation and attenuated endothelial damage by increasing pVASP protein levels in HR-induced endothelial dysfunction in isolated rat CA. This experiment demonstrated that SCU can perform vascular endothelial protection through the PKG pathway. In conclusion, SCU can protect the cardiovascular system by activating the eNOS/cGMP/PKG signal pathway (Figure 5).