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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2008-12-5
pubmed:abstractText
Hepatic blood supply is uniquely regulated by the hepatic arterial buffer response (HABR), counteracting alterations of portal venous blood flow by flow changes of the hepatic artery. Hydrogen sulfide (H(2)S) has been recognized as a novel signaling molecule with vasoactive properties. However, the contribution of H(2)S in mediating the HABR is not yet studied. In pentobarbital-anesthetized and laparotomized rats, flow probes around the portal vein and hepatic artery allowed for assessment of the portal venous (PVBF) and hepatic arterial blood flow (HABF) under baseline conditions and stepwise reduction of PVBF for induction of HABR. Animals received either the H(2)S donor Na(2)S, DL-propargylglycine as inhibitor of the H(2)S synthesizing enzyme cystathionine-gamma-lyase (CSE), or saline alone. Additionally, animals were treated with Na(2)S and the ATP-sensitive potassium channel (K(ATP)) inhibitor glibenclamide or with glibenclamide alone. Na(2)S markedly increased the buffer capacity to 27.4 +/- 3.0% (P < 0.05 vs. controls: 15.5 +/- 1.7%), whereas blockade of H(2)S formation by DL-propargylglycine significantly reduced the buffer capacity (8.5 +/- 1.4%). Glibenclamide completely reversed the H(2)S-induced increase of buffer capacity to the control level. By means of RT-PCR, Western blot analysis, and immunohistochemistry, we observed the expression of both H(2)S synthesizing enzymes (CSE and cystathionine-beta-synthase) in aorta, vena cava, hepatic artery, and portal vein, as well as in hepatic parenchymal tissue. Terminal branches of the hepatic afferent vessels expressed only CSE. We show for the first time that CSE-derived H(2)S contributes to HABR and partly mediates vasorelaxation of the hepatic artery via activation of K(ATP) channels.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0193-1857
pubmed:author
pubmed:issnType
Print
pubmed:volume
295
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
G1266-73
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
H2S contributes to the hepatic arterial buffer response and mediates vasorelaxation of the hepatic artery via activation of K(ATP) channels.
pubmed:affiliation
Institute for Experimental Surgery, University of Rostock, Rostock, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't