Pathophysiological role of endothelins in pulmonary microcirculatory disorders due to intestinal ischemia and reperfusion.
BACKGROUND
This study was conducted to investigate pulmonary microcirculatory disorders caused by intestinal ischemia reperfusion (IIR), and the pathophysiological roles of endothelin (ET) in acute lung injury (ALI).


METHODS
Male rats were pretreated with normal saline or a nonselective ET receptor antagonist (TAK-044) and subjected to IIR (60 min of intestinal ischemia and 180 min of reperfusion). The right upper lobe of the lung was examined by intravital confocal microscopy.


RESULTS
The size of arterioles and venules was not significantly reduced during IIR, but the functional capillary density (FCD) decreased significantly. TAK-044 improved the pulmonary microhemodynamics, inhibiting the accumulation of leukocytes, the pulmonary edema, and the decrease of FCD.


CONCLUSIONS
In the early stage of IIR, pulmonary microhemodynamics seemed more likely to be disturbed by the decrease of FCD, than by arteriolar or venular vasoconstriction. ETs decrease the FCD, promoting the interaction between leukocytes and pulmonary vessels.
Mitsuoka
H
H
Second Department of Surgery, Hamamatsu University School of Medicine, Hamamatsu, Japan.
Unno
N
N
Sakurai
T
T
Kaneko
H
H
Suzuki
S
S
Konno
H
H
Terakawa
S
S
Nakamura
S
S
D000818:Animals; D016232:Endothelins / Q000502:physiology*; D006439:Hemodynamics / Q000187:drug effects; D007422:Intestines / Q000098:blood supply*; D007511:Ischemia / Q000503:physiopathology*; D008297:Male; D008833:Microcirculation; D009504:Neutrophils / Q000502:physiology; D010456:Peptides, Cyclic / Q000494:pharmacology; D011652:Pulmonary Circulation; D011654:Pulmonary Edema / Q000209:etiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D015424:Reperfusion
D016232:Endothelins; D010456:Peptides, Cyclic; C088196:TAK 044