| First Author | Cao X | Year | 2007 |
| Journal | Brain Res | Volume | 1163 |
| Pages | 33-43 | PubMed ID | 17632091 |
| Mgi Jnum | J:123769 | Mgi Id | MGI:3719517 |
| Doi | 10.1016/j.brainres.2007.04.085 | Citation | Cao X, et al. (2007) Effects of capsaicin on VGSCs in TRPV1(-/-) mice. Brain Res 1163:33-43 |
| abstractText | Two different mechanisms by which capsaicin blocks voltage-gated sodium channels (VGSCs) were found by using knockout mice for the transient receptor potential V1 (TRPV1(-/-)). Similar with cultured rat trigeminal ganglion (TG) neurons, the amplitude of tetrodotoxin-resistant (TTX-R) sodium current was reduced 85% by 1 muM capsaicin in capsaicin sensitive neurons, while only 6% was blocked in capsaicin insensitive neurons of TRPV1(+/+) mice. The selective effect of low concentration capsaicin on VGSCs was reversed in TRPV1(-/-) mice, which suggested that this effect was dependent on TRPV1 receptor. The blockage effect of high concentration capsaicin on VGSCs in TRPV1(-/-) mice was the same as that in capsaicin insensitive neurons of rats and TRPV1(+/+) mice. It is noted that non-selective effect of capsaicin on VGSCs shares many similarities with local anesthetics. That is, firstly, both blockages are concentration-dependent and revisable. Secondly, being accompanied with the reduction of amplitude, voltage-dependent inactivation curve shifts to hyperpolarizing direction without a shift of activation curve. Thirdly, use-dependent blocks are induced at high stimulus frequency. |
