Nitric Oxide Protects L-Type Calcium Channel of Cardiomyocyte during Long-Term Isoproterenol Stimulation in Tail-Suspended Rats.
BIOMED RESEARCH INTERNATIONAL 2015;
2015:780814. [PMID:
26167497 PMCID:
PMC4488016 DOI:
10.1155/2015/780814]
[Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 05/30/2015] [Indexed: 12/14/2022]
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 (ICa,L) in the SUS group was less than that in the CON group. The maximal ICa,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 ICa,L to 50% of initial value in the CON group; in contrast, NO donor SNAP maintained maximal ICa,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.
Collapse