AUTHOR=Noorani Muzamil M., Noel Rebecca C., Marrelli Sean TITLE=Upregulated TRPC3 and Downregulated TRPC1 Channel Expression during Hypertension is Associated with Increased Vascular Contractility in Rat JOURNAL=Frontiers in Physiology VOLUME=2 YEAR=2011 URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2011.00042 DOI=10.3389/fphys.2011.00042 ISSN=1664-042X ABSTRACT=
Transient receptor potential (TRP) C1 and C3 (TRPC1 and TRPC3) are expressed in vascular smooth muscle cells and are thought to be involved in vascular contractility. In the present study, we determined the effect of systemic hypertension on TRPC1/TRPC3 channel expression and vascular contractility in rat carotid artery (CA). CA were studied from male spontaneously hypertensive rats (SHR), Wistar-Kyoto (WKY), and Long Evans (LE) rats. TRPC1/3 expression was determined by RT-PCR and Western blot. TRP channel function was evaluated by whole-cell patch clamp, using UTP (60 μM) to stimulate TRPC1/3 channels. Contractions of endothelium-denuded CA segments to UTP (1–300 μM) and phenylephrine (Phe; 0.1 nM–10 μM) were measured in an isometric tension bath. TRPC1 and TRPC3 mRNA was present in CA of both WKY and SHR. Western blot demonstrated 3.1 ± 1.2 times greater TRPC3 expression and 0.5 ± 0.2 times TRPC1 in SHR versus WKY CA. Isolated CA showed potentiated contraction to UTP in the SHR versus WKY. Activation of voltage-dependent Ca2+ channels (VDCC) in UTP-mediated constriction only occurred in SHR CA. Contraction to Phe was unaltered between WKY and SHR CA and involved equal significant VDCC activation in both groups. Patch clamp demonstrated that the UTP-stimulated current (