[Changes of blood vessel active substances in acute pulmonary embolism induced by echinococus granulous cyst in rabbits].

OBJECTIVE

To investigate the role of blood vessel active substances, such as endothelin-1 (ET-1), thromboxane B(2) (TXB(2)), and 6-keto-prostaglandin F(1alpha) (6-K-PGF(1alpha)) in a rabbit model of acute pulmonary embolism induced by echinococus granulous cyst.

METHODS

Catheters were placed into the femoral artery and the femoral vein. Saline, fresh clear cyst fluid or sand containing cyst fluid in a volume of 2 ml/kg were infused through the femoral vein catheter. Changes of ET-1, TXB(2) and 6-K-PGF(1alpha) were measured; PaO(2), PaCO(2), pH, MAP, heart rate, and respiration rate were recorded; and radionuclide lung perfusion scan and the change of heart and lung pathology were studied.

RESULTS

The changes of the studied parameters were not remarkable in the saline treated animals (P > 0.05). TXB(2) and 6-K-PGF(1alpha) were elevated in the cyst fluid treated animals (P < 0.05). PaO(2), PaCO(2), and MAP declined in the clear cyst fluid group (P < 0.05), but their changes were more significant in animals treated with sand containing cyst fluid. Radionuclide lung perfusion scan showed radioactivity defect or attenuation. Histological examination of the lungs revealed diffuse alveolar damage.

CONCLUSIONS

Sand containing cyst fluid caused a more severe disease in this rabbit model of acute pulmonary embolism, suggesting that it played an important role in the induction of lung damage.