Lung injury from gut ischemia: insensitivity to portal blood flow diversion.
Gut ischemia/reperfusion (I/R) appears to produce pulmonary vascular injury through endotoxin release and cytokine activation. The ability of hepatic reticuloendothelial cells to clear bacterial products may also be impaired during I/R. To test this, diversion of the splanchnic blood flow from the liver into the systemic circulation was performed via a microsurgical portacaval transposition in anesthetized Sprague-Dawley rats (275-375 g). Shunted animals underwent portacaval transposition and were allowed to recover for 7-10 days; sham animals underwent exploration but no shunt was created. The I/R animals were subjected to 60 minutes of reperfusion. All shunts were patent at autopsy. Pulmonary vascular permeability was assessed by measuring tissue retention of Evans blue dye. Gut I/R produced significant increases in pulmonary vascular permeability (46.2% +/- 11.0% vs. 16.4% +/- 3.8% [I/R vs. control]; p < 0.05) regardless of the presence of hepatic bypass (32.7% +/- 9.0% vs. 10.0% +/- 1.4% [I/R vs. control]; p < 0.05). These data indicate that a mediator or mediators of gut origin are responsible for pulmonary vascular permeability changes following gut I/R and are not appreciably modulated by the liver.
Johnston
T D
TD
Department of Surgery, University of Texas Medical School at Houston 77030.
Fischer
R
R
Chen
Y
Y
Reed
R L
RL
D000818:Animals; D002199:Capillary Permeability; D004731:Endotoxins / Q000097:blood; D007422:Intestines / Q000098:blood supply* / Q000503:physiopathology; D007511:Ischemia / Q000150:complications / Q000503:physiopathology*; D008099:Liver / Q000098:blood supply / Q000502:physiology*; D008102:Liver Circulation / Q000502:physiology*; D008168:Lung / Q000502:physiology*; D008171:Lung Diseases / Q000209:etiology; D008297:Male; D008638:Mesenteric Arteries / Q000503:physiopathology; D011170:Portasystemic Shunt, Surgical; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000150:complications / Q000503:physiopathology*
D004731:Endotoxins