Antecedent hydrogen sulfide elicits an anti-inflammatory phenotype in postischemic murine small intestine: role of BK channels.
The objectives of this study were to determine the role of calcium-activated, small (SK), intermediate (IK), and large (BK) conductance potassium channels in initiating the development of an anti-inflammatory phenotype elicited by preconditioning with an exogenous hydrogen sulfide (H(2)S) donor, sodium hydrosulfide (NaHS). Intravital microscopy was used to visualize rolling and firmly adherent leukocytes in vessels of the small intestine of mice preconditioned with NaHS (in the absence and presence of SK, IK, and BK channel inhibitors, apamin, TRAM-34, and paxilline, respectively) or SK/IK (NS-309) or BK channel activators (NS-1619) 24 h before ischemia-reperfusion (I/R). I/R induced marked increases in leukocyte rolling and adhesion, effects that were largely abolished by preconditioning with NaHS, NS-309, or NS-1619. The postischemic anti-inflammatory effects of NaHS-induced preconditioning were mitigated by BKB channel inhibitor treatment coincident with NaHS, but not by apamin or TRAM-34, 24 h before I/R. Confocal imaging and immunohistochemistry were used to demonstrate the presence of BKα subunit staining in both endothelial and vascular smooth muscle cells of isolated, pressurized mesenteric venules. Using patch-clamp techniques, we found that BK channels in cultured endothelial cells were activated after exposure to NaHS. Bath application of the same concentration of NaHS used in preconditioning protocols led to a rapid increase in a whole cell K(+) current; specifically, the component of K(+) current blocked by the selective BK channel antagonist iberiotoxin. The activation of BK current by NaHS could also be demonstrated in single channel recording mode where it was independent of a change in intracellular Ca(+) concentration. Our data are consistent with the concept that H(2)S induces the development of an anti-adhesive state in I/R in part mediated by a BK channel-dependent mechanism.
Zuidema
Mozow Y
MY
Department of Medical Pharmacology and Physiology, Dalton Cardiovascular Research Center, University of Missouri School of Medicine, Columbia, Missouri 65212, USA.
Yang
Yan
Y
Wang
Meifang
M
Kalogeris
Theodore
T
Liu
Yajun
Y
Meininger
Cynthia J
CJ
Hill
Michael A
MA
Davis
Michael J
MJ
Korthuis
Ronald J
RJ
D000818:Animals; D001030:Apamin / Q000494:pharmacology; D002478:Cells, Cultured; D055724:Electrophysiological Phenomena; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000503:physiopathology; D006801:Humans; D006862:Hydrogen Sulfide / Q000494:pharmacology / Q000627:therapeutic use*; D007249:Inflammation / Q000503:physiopathology / Q000517:prevention & control*; D007421:Intestine, Small / Q000098:blood supply*; D007511:Ischemia / Q000150:complications* / Q000503:physiopathology; D019194:Ischemic Preconditioning; D051036:Large-Conductance Calcium-Activated Potassium Channels / Q000187:drug effects / Q000502:physiology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D023421:Models, Animal; D010455:Peptides / Q000494:pharmacology; D010641:Phenotype; D011720:Pyrazoles / Q000494:pharmacology
D051036:Large-Conductance Calcium-Activated Potassium Channels; D010455:Peptides; D011720:Pyrazoles; C411671:TRAM 34; D001030:Apamin; C064719:iberiotoxin; D006862:Hydrogen Sulfide