FIGURE 11.

Transient receptor potential canonical channel in healthy and mdx VSMCs. Schematic representation of TRPC channels isoforms and the effect of diacylglycerol (DAG) on intracellular [Ca^{2 +} ] and [Na⁺] in healthy (A) and in mdx VSMC (B). Binding of the agonist to the G-protein-coupled receptor leads to phospholipase C (PLC) activation. The activation of PLC hydrolyzes phosphatidyl 4-5 biphosphate PI(4,5)P2 to produce diacylglycerol (DAG) and IP3. DAG contributes to TRPC3 and TRPC6 channels, but also TRPC1 activation under heteromeric complexes allowing Ca²⁺ and Na⁺ influx into the vascular muscle cell. A chronic increase in Ca²⁺ and Na⁺ flux through the upregulated TRPC channels in mdx VSMCs contribute to the observed elevate [Ca²⁺]_i and [Na⁺]_i.