Referenced in: none

Automatically associated channels: Cav2.3

Title: Modified sympathetic regulation in N-type calcium channel null-mouse.

Authors: Manabu Murakami, Takayoshi Ohba, Tsai-Wen Wu, Susumu Fujisawa, Takashi Suzuki, Yoichiro Takahashi, Eiki Takahashi, Hiroyuki Watanabe, Ichiro Miyoshi, Kyoichi Ono, Hironobu Sasano, Hiroshi Ito, Toshihiko Iijima

Journal, date & volume: Biochem. Biophys. Res. Commun., 2007 Mar 23 , 354, 1016-20

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/17275790

Abstract
To elucidate the physiological importance of neuronal (N)-type calcium channels in sympathetic controls, we analyzed N-type channel-deficient (NKO) mice. Immunoprecipitation analysis revealed increased interaction between beta3 (a major accessory subunit of N-type channels) and R-type channel-forming CaV2.3 in NKO mice. R-R intervals in NKO ECG recordings were elongated and fluctuating, suggesting disturbed sympathetic tonus. N-type channel inhibitors elongated the R-R interval in control mice, whereas R-type channel blocking with SNX-482 significantly affected NKO but not control mice, indicating a compensatory role for R-type channels. Echocardiography and Langendorff heart analysis confirmed a major role for R-type channels in NKO mice. Combined, our biochemical and physiological analyses strongly suggest that the remaining sympathetic tonus in NKO mice is dependent on R-type calcium channels.