Evidence for a functional link between stress response and vascular control in hepatic portal circulation.
Heme oxygenase (HO)-derived carbon monoxide (CO) may contribute to vascular control through elevation of guanosine 3',5'-cyclic monophosphate. In the present study, we investigated the functional significance of expression of the isoenzyme HO-1 (heat-shock protein 32) in liver after hemorrhage/resuscitation (H/R) in rats anesthetized with pentobarbital sodium. An increase of mRNA levels for HO-1 was observed at 3 h after resuscitation, followed by induction of the protein at 6 h in pericentral hepatocytes and sinusoidal lining cells. Concomitantly, lower portal resistance was observed in H/R (0.33 +/- 0.060 mmHg.ml-1.min) compared with control rats (0.47 +/- 0.035 mmHg.ml-1.min). Blockade of the HO-CO pathway by tin protoporphyrin-IX (SnPP-IX) led to a transient increase in portal pressure with no effect on portal low in controls, whereas an increase in pressure and a decrease in flow contributed to the sustained increase in portal resistance after H/R. These results indicate that HO contributes to maintenance of hepatic perfusion in vivo under stressful conditions, suggesting a functional link between stress response and vascular control in portal circulation.
Bauer
M
M
Department of Anesthesiology and Critical Care Medicine, University of the Saarland, Homburg, Germany.
Pannen
B H
BH
Bauer
I
I
Herzog
C
C
Wanner
G A
GA
Hanselmann
R
R
Zhang
J X
JX
Clemens
M G
MG
Larsen
R
R
D000818:Animals; D001794:Blood Pressure; D004790:Enzyme Induction; D006419:Heme Oxygenase (Decyclizing) / Q000096:biosynthesis*; D007527:Isoenzymes / Q000096:biosynthesis; D007700:Kinetics; D008099:Liver / Q000201:enzymology* / Q000503:physiopathology; D008297:Male; D011168:Portal System / Q000187:drug effects; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D012016:Reference Values; D012151:Resuscitation; D012771:Shock, Hemorrhagic / Q000201:enzymology / Q000503:physiopathology*; D013997:Time Factors; D014158:Transcription, Genetic; D014655:Vascular Resistance
D007527:Isoenzymes; D012333:RNA, Messenger; D006419:Heme Oxygenase (Decyclizing)