(Sub)family feud: crosstalk between TRPC channels in vascular smooth muscle cells during vasoconstrictor agonist stimulation.

摘要

Agonist-dependent activation of non-selective cation channels belonging to the canonical (C) transient receptor potential (TRP) subfamily has a profound influence on vascular tone (Inoue et al. 2001) and proliferation (Abramowitz & Birnbaumer, 2009) of arterial myocytes, responses that can contribute to cardiovascular diseases such as hypertension and atherosclerosis. TRPC channels are indirectly sensitive to extracellular substances. Vasoactive molecules binding to specific G-protein-coupled receptors (GPCRs) on the plasma membrane of smooth muscle cells (SMCs) activate intracellular signalling pathways leading to increased influx of Na~+ and Ca~(2+). Cation entry depolarizes the sarcolemma and increases Ca~(2+) influx via voltage-dependent Ca~(2+) channels, thereby elevating myocyte contractility and activating other Ca~(2+)-dependent pathways. TRPC-mediated Ca~(2+) entry may also directly influence SMC function.