R. Pararajasingam et al., Pulmonary nitric oxide metabolism following infrarenal aortic cross-clamp-induced ischaemia-reperfusion injury, EUR J VAS E, 19(1), 2000, pp. 47-51
Citations number
24
Categorie Soggetti
Surgery
Journal title
EUROPEAN JOURNAL OF VASCULAR AND ENDOVASCULAR SURGERY
Objectives: to investigate endogenous pulmonary nitric oxide metabolism fol
lowing infrarenal aortic cross-clamp-induced ischaemia-reperfusion injury.
Methods: groups of male Wistar rats (n=6) curve subjected to 60 minutes of
infrarenal aortic cross-clamping under general anaesthesia. Rats were culle
d after 0, 60 and 120 minutes' reperfusion, following release of the aortic
clamp. A sham-operated control group was also studied. Acute lung injury (
ALI) was quantified by measuring the protein concentration in lung bronchoa
lveolar lavage (BAL) fluid. Pulmonary myeloperoxidase activity (MPO) was me
asured as an index of neutrophil infiltration and degranulation in the lung
. Plasma tumour-necrosis factor-alpha (TNF-alpha) was measured as an index
of the pro-inflammatory cytokine response and pulmonary nitric oxide syntha
se (NOS) activity was determined by measuring conversion of H-3 L-arginine
to H-3 L-citrulline in tissue homogenates.
Results: these data show significant ALI with increased pulmonary microvasc
ular permeability and MPO activity in animals subject to 60 minutes' ischae
mia and 60 minutes or 120 minutes of reperfusion compared to control animal
s (P<0.01). Plasma TNF-alpha levels were significantly increased following
60 minutes of ischaemia compared to controls (p<0.01) and remained signific
antly increased in animals subject to reperfusion (P<0.01). Pulmonary NOS a
ctivity was significantly increased in animals subject to reperfusion (p<0.
01).
Conclusions: the reperfusion phase of infrarenal aortic cross-clamping prov
okes a significant increase in pulmonary NOS metabolism. The increase in pl
asma TNF-alpha and MPO activity suggests that this response may be secondar
y to inducible NOS expression. Manipulation of this response may benefit pa
tients at risk of acute injury following infrarenal aortic reconstruction.