Referenced in: none

Automatically associated channels: Cav2.1

Title: Modified autonomic regulation in mice mutated in the β4 subunit of the lh/lh calcium channel.

Authors: Manabu Murakami, Takashi Suzuki, Tsai-Wen Wu, Kenji Kuwasako, Eiki Takahashi, Hiroyuki Watanabe, Agnieszka M Murakami, Ichiro Miyoshi, Teruyuki Yanagisawa, Hironobu Sasano, Kyoichi Ono, Takayoshi Ohba

Journal, date & volume: Biochem. Biophys. Res. Commun., 2015 May 29 , 461, 200-5

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/25892515

Abstract
Genetic analyses have revealed an important association between P/Q-type calcium channel activities and hereditary neurological disorders. The P/Q-type channels are composed principally of heterologous multimeric subunits including CaV2.1 and CaVβ4. Of these, the β4 subunit is thought to play a significant role in channel physiology, because a mouse line mutant in that subunit (the lethargic mouse: lh) exhibits a severe ataxic phenotype. The aim of the present study was to elucidate the physiological importance of the β4 subunit. ECG analysis showed that the T wave was high in 8-week-old lh mutants; this may be associated with hyperkalemia. Upon pharmacological ECG analysis, 2-3-week-old lh mutants exhibited reduced responses to a β-blocker and a muscarinic receptor antagonist. Analysis of heart rate variability revealed that the R-R interval was unstable in lh mutants and that both the low- and high-frequency components had increased in extent, indicating that the tonus of both the sympathetic and parasympathetic nervous systems was modified. Thus, our present study revealed that the β4 subunit played a significant role in regulation of sympathetic and parasympathetic nerve activities.