Changes of Hypoxic Pulmonary Vasoconstriction in Isolated Endotoxin-Treated Rat Lungs / 대한마취과학회지

ABSTRACT

BACKGROUND: Several investigations have studied hypoxic pulmonary vasoconstriction (HPV) during endotoxemia and there is an increase in nitric oxide (NO) in pulmonary vessels. However, these studies yielded conflicting or at times contradictory results, since reference has been made to both enhancement and inhibition of HPV. Our objective was to determine the changes of hypoxic pulmonary vasoconstriction on the isolated blood-perfused lung of endotoxemic rats. METHODS: Pulmonary arterial pressure (PAP) was measured in a blood-perfused lung preparation from Sprague-Dawley rats in normoxia (21% O2, 5% CO2, balanced N2) and hypoxia (5% O2, 5% CO2, balanced N2). We studied the effect of normoxia and hypoxia in a control group, Escherichia coli lipopolysaccharide group (LPS) and LPS with N omega-nitro-L-arginine methyl ester group (L-NAME). RESULTS: The Baseline PAP was higher in LPS (15.0+/-4.0 mmHg) compared with control group (10.9+/-2.9 mmHg) and L-NAME (11.1+/-3.6 mmHg). In hypoxia, HPV was higher in L-NAME (109.6+/-100.2%) compared with control group (59.9+/-31.6%) and LPS (58.8+/-33.8%)(P<0.05). CONCLUSIONS: We conclude that NO is an important factor to impair HPV during endotoxemia.