Korean J Radiol.  2004 Sep;5(3):149-156. 10.3348/kjr.2004.5.3.149.

Hepatopulmonary Syndrome Induced by Common Bile Duct Ligation in a Rabbit Model: Correlation between Pulmonary Vascular Dilatation on Thin-Section CT and Angiography and Serum Nitrite Concentration or Endothelial Nitric Oxide Synthase (eNOS) 1 Expression

• Lee KN
• Yoon SK
• Lee JW
• Kim KN
• Park BH
• Kwak JY
• Jeong JS
• Kim YH

• KMID: 1118819
• DOI: http://doi.org/10.3348/kjr.2004.5.3.149

Abstract

OBJECTIVE
To investigate the correlation between radiologic vascular dilatation and serum nitrite concentration and eNOS expression in the endothelial cell and pneumocyte in a rabbit model of hepatopulmonary syndrome induced by common bile duct ligation (CBDL). MATERIALS AND METHODS: Thin-section CT scans of the lung and pulmonary angiography were obtained 3 weeks after CBDL (n=6), or a sham operation (n=4), and intrapulmonary vasodilatation was assessed. The diameter and tortuosity of peripheral vessels in the right lower lobe by thin-section CT and angiography at the same level of the right lower lobe in all subjects were correlated to serum nitrite concentration and eNOS (endothelial nitric oxide synthase) expression as determined by immunostaining. RESULTS: The diameters of pulmonary vessels on thin-section CT were well correlated with nitrite concentrations in serum (r = 0.92, p < 0.001). Dilated pulmonary vessels were significantly correlated with an increased eNOS expression (r = 0.94, p < 0.0001), and the severity of pulmonary vessel tortuosity was found to be well correlated with serum nitrite concentration (r = 0.90, p < 0.001). CONCLUSION: The peripheral pulmonary vasculature in hepatopulmonary syndrome induced by CBLD was dilated on thin-section CT and on angiographs. Our findings suggest that peripheral pulmonary vascular dilatations are correlated with serum nitrite concentrations and pulmonary eNOS expression.

Keyword

Liver, injuries; Lung, angiography; Lung, CT; Lung, injuries

MeSH Terms

Angiography
Animals
Common Bile Duct/injuries
Dilatation, Pathologic/radiography
Disease Models, Animal
Endothelium, Vascular/metabolism
Hepatopulmonary Syndrome/etiology/*metabolism
Ligation
Lung/*blood supply/metabolism/*radiography
Nitric-Oxide Synthase/*metabolism
Nitrites/*blood
Pulmonary Artery/radiography
Rabbits
Research Support, Non-U.S. Gov't
Tomography, X-Ray Computed/methods

Figure

• 

  Fig. 1 Hepatopulmonary syndrome (case 2) induced by 3 weeks after common bile duct ligation in a rabbit. A. Transverse thin-section CT scan obtained at the lower lobe showing markedly dilated peripheral pulmonary vessel (arrow) compared with vessels at the same level in Figs. 2, 3A. B. Pulmonary angiograph obtained at a 25 degree oblique angle showing severe tortuous right basal arteries (arrow). C. Immunostaining for endothelial nitric oxide synthase in the right lower lobe near the level of A showing strong red immunostaining both in vascular endothelial cells (arrows) and in pneumocytes (arrowheads) (score 2).

• 

  Fig. 2 Hepatopulmonary syndrome (case 1) induced 3 weeks after common bile duct ligation in a rabbit. A. Transverse thin-section CT scan obtained at the same level of Fig. 1A shows moderately dilated peripheral pulmonary vessels (arrow) versus vessels at the same level in Figs. 1 and 3A. B. Pulmonary angiograph obtained at a 25 degree oblique angle showing mild tortuous right basal arteries (arrow). C. Immunostaining for endothelial nitric oxide synthase in the right lower lobe near the level of A showing slight red immunostaining in vascular endothelial cells (arrows) and in pneumocytes (arrowheads) (score 1).

• 

  Fig. 3 Control (case 7) - sham operation without common bile duct ligation. A. Transverse thin-section CT scan obtained at the same level as Figs. 1 and 2A, showing no evidence of a dilated peripheral pulmonary vessel (arrow) compared with vessels at the same level in Figs. 1 and 2A. B. Pulmonary angiographs obtained at a 25 degree oblique angle showing no evidence of tortuosity of the right basal arteries (arrow). C. Immunostaining for endothelial nitric oxide synthase in the right lower lobe near the level of A. Vascular endothelial cells show slight immunoreactivity but no definite pneumocyte immunostaining (score 0).

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  Fig. 4 Correlation between peripheral pulmonary vessel diameter and serum nitrite concentration in 6 animals 3 weeks after common bile duct ligation and in four animals in the control group. Peripheral pulmonary vessel diameter was found to correlate significantly with serum nitrite concentration (r = 0.92, p < 0.001).

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