Correlation between pulmonary endothelin receptors and alveolar-arterial oxygen gradient in rats with hepatopulmonary syndrome

Abstract

The correlation between pulmonary endothelin receptors and alveolar-arterial oxygen gradient (A-aDO₂) in rats with hepatopulmonary syndrome was investigated. Animals were divided into 2 groups: Sham-operated (Sham) group and common bile duct ligation (CBDL) group. Arterial blood gas was evaluated by a blood gas analyzer. The concentrations of ET-1 in blood and lung tissue sample were evaluated by radioimmunoassay. The distribution and expression of two kinds of subtype receptor of ET-1, ETRA and ETRB were examined byin situ hybridization. The results showed that the level of A-aDO₂ was higher in CBDL group were both higher than in Sham group (P<0.05). There was no significant difference in averageA of ETRA between two groups by imaging analysis (0.21±0.06vs 0.22±0.08,P>0.05), while that of ETRB was higher in CBDL group than in Sham group (0.58±0.16vs 0.28±0.07,P<0.05). The expression of ETRB in lung was positively correlated with A-aDO₂(P<0. 05). It was concluded that the widened A-aDO₂ may be related with enhancement of the expression of ETRB in lung.

Keywords

hepatopulmonary syndrome / endothelin receptor A / endothelin receptor B / alveolar-arterial oxygen gradient