title: Nitric Oxide Protects L-Type Calcium Channel of Cardiomyocyte during Long-Term Isoproterenol Stimulation in Tail-Suspended Rats.
abstract: The aim of this study was to investigate the effects of nitric oxide (NO) and reactive oxygen species (ROS) on L-type calcium channel (LTCC) gating properties of cardiomyocytes during long-term isoproterenol (ISO) stimulation. Expression and activity of nNOS as well as S-nitrosylation of LTCC α1C subunit significantly decreased in the myocardium of SUS rats. Long-term ISO stimulation increased ROS in cardiomyocytes of SUS rats. ISO-enhanced calcium current (I Ca,L) in the SUS group was less than that in the CON group. The maximal I Ca,L decreased to about 80% or 60% of initial value at the 50th minute of ISO treatment in CON or SUS group, respectively. Specific inhibitor NAAN of nNOS reduced maximal I Ca,L to 50% of initial value in the CON group; in contrast, NO donor SNAP maintained maximal I Ca,L in SUS group to similar extent of CON group after 50 min of ISO treatment. Long-term ISO stimulation also changed steady-state activation (P < 0.01), inactivation (P < 0.01), and recovery (P < 0.05) characteristics of LTCC in SUS group. In conclusion, NO-induced S-nitrosylation of LTCC α1C subunit may competitively prevent oxidation from ROS at the same sites. Furthermore, LTCC can be protected by NO during long-term ISO stimulation.
authors.affiliation: Department of Aerospace Physiology, Fourth Military Medical University, No. 169 Changlexi Road, Xi'an 710032, China.
authors.forename: Zhi-Jie
authors.initials: ZJ
authors.lastname: Yue
authors.affiliation: Department of Aerospace Physiology, Fourth Military Medical University, No. 169 Changlexi Road, Xi'an 710032, China.
authors.forename: Peng-Tao
authors.initials: PT
authors.lastname: Xu
authors.affiliation: Department of Aerospace Physiology, Fourth Military Medical University, No. 169 Changlexi Road, Xi'an 710032, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Jiao
authors.affiliation: Department of Aerospace Physiology, Fourth Military Medical University, No. 169 Changlexi Road, Xi'an 710032, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Chang
authors.affiliation: Department of Aerospace Physiology, Fourth Military Medical University, No. 169 Changlexi Road, Xi'an 710032, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Song
authors.affiliation: Department of Aerospace Physiology, Fourth Military Medical University, No. 169 Changlexi Road, Xi'an 710032, China.
authors.forename: Man-Jiang
authors.initials: MJ
authors.lastname: Xie
authors.affiliation: Department of Aerospace Physiology, Fourth Military Medical University, No. 169 Changlexi Road, Xi'an 710032, China.
authors.forename: Zhi-Bin
authors.initials: ZB
authors.lastname: Yu
mesh_terms: D000818:Animals; D020746:Calcium Channels, L-Type / Q000378:metabolism*; D002316:Cardiotonic Agents / Q000494:pharmacology*; D018475:Head-Down Tilt / Q000502:physiology; D007545:Isoproterenol / Q000494:pharmacology*; D008297:Male; D032383:Myocytes, Cardiac / Q000378:metabolism* / Q000502:physiology; D009569:Nitric Oxide / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013481:Superoxides / Q000378:metabolism
chemical_list: D020746:Calcium Channels, L-Type; D002316:Cardiotonic Agents; C419385:L-type calcium channel alpha(1C); D013481:Superoxides; D009569:Nitric Oxide; D007545:Isoproterenol