title: Sulfur dioxide derivatives depress L-type calcium channel in rat cardiomyocytes.
abstract: 1. Sulfur dioxide (SO(2) ) has recently been found to have various biological effects on the cardiovascular system. The present study was designed to explore the effects of SO(2) derivatives on the L-type calcium current (I (Ca, L) ) in isolated rat ventricular cardiomyocytes. 2. A Langendorf system was used to dissociate single ventricular cells. SO(2) derivatives from 5 to 1000 μmol/L were incubated with cardiomyocytes. The whole-cell patch-clamp technique was used to record I (Ca, L) . The effect of SO(2) derivatives on intracellular calcium concentration ([Ca(2+) ](i) ) was detected by confocal microscopy. 3. Concentrations of 5 or 10 μmol/L SO(2) derivatives could not change I (Ca, L) evoked by a single pulse from -40 to 0 mV for 200 ms in rat ventricular cardiomyocytes; however, 50, 100, 500 or 1000 μmol/L SO(2) derivatives could depress the peak amplitudes of calcium currents in 6 min, and the I (Ca, L) was attenuated by 13.19%, 16.59%, 21.23% and 24.72%, respectively, as compared with corresponding controls (P < 0.05). The 50, 100, 500 or 1000 μmol/L SO(2) derivatives also depressed the peak I-V curves, without altering the reversal potential and the voltage dependence of the peak I (Ca, L) . Therefore, 1000 μmol/L SO(2) derivatives could reduce [Ca(2+) ](i) in cardiomyocytes. 4. The results of the present study suggest that SO(2) derivatives can depress I (Ca, L) in cardiomyocytes, which might have a protective effect in cardiovascular diseases.
authors.affiliation: Departments of Pediatrics, Institute of Cardiovascular Research, Peking University First Hospital, Beijing, China.
authors.forename: Rong-Yuan
authors.initials: RY
authors.lastname: Zhang
authors.forename: Jun-Bao
authors.initials: JB
authors.lastname: Du
authors.forename: Yan
authors.initials: Y
authors.lastname: Sun
authors.forename: Stella
authors.initials: S
authors.lastname: Chen
authors.forename: Hao-Jan
authors.initials: HJ
authors.lastname: Tsai
authors.forename: Lan
authors.initials: L
authors.lastname: Yuan
authors.forename: Lin
authors.initials: L
authors.lastname: Li
authors.forename: Chao-Shu
authors.initials: CS
authors.lastname: Tang
authors.forename: Hong-Fang
authors.initials: HF
authors.lastname: Jin
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D020746:Calcium Channels, L-Type / Q000378:metabolism*; D006352:Heart Ventricles / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D018613:Microscopy, Confocal; D032383:Myocytes, Cardiac / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D018408:Patch-Clamp Techniques / Q000379:methods; D051381:Rats; D017207:Rats, Sprague-Dawley; D013458:Sulfur Dioxide / Q000494:pharmacology*
chemical_list: D020746:Calcium Channels, L-Type; D013458:Sulfur Dioxide; D002118:Calcium