[Therapeutic effect of somatostatin on acute respiratory distress syndrome in experimental rats].

Objective: This study was aimed to assess the effects of somatostatin (SST) and its analog Octreotide on the treatment of acute respiratory distress syndrome (ARDS) in rat model.

Methods: ARDS rat model was induced by administration of paraquat. After 24 hours oral administration of paraquat, three drugs (SST, Octreotide and dexamethasone at dosage of 1 mg/kg, 0.1 mg/kg and 1 mg/kg respectively) were infused into the tail veins of rats so as to form three treatment groups. The rats given only paraquat were subjects in the ARDS group. PaO2 level and pulmonary coefficient were detected, and the morphological changes of lungs were examined. In addition, TNF-alpha and IL-6 levels in plasma, Bronchoalveolar lavage fluids (BALF) and intestine homogenate were measured respectively.

Results: The ARDS rats treated with SST, Octreotide and dexamethasone showed mitigation of inflammatory response in the lungs, improvement in lung ventilation, reduction of pulmonary coefficient (-13%-15%), increase in PaO2 level (+75%-84%), decrease in PaCO2 level (-17%-22%), and restoration of pH value to normal in plasma, when compared with the rats of ARDS group. TNF-alpha level in plasma tended to decline (P>0.05); it significantly lowered in BALF and intestine homogenate in the ARDS rats treated (P< 0.05). IL-6 level in BALF tended to be lower in treatment group (P>0.05), but the IL-6 level in plasma and intestine homogenate displayed no significant difference between the treatment group and ARDS group.

Conclusions: These results suggest that SST and its analog Octreotide assume a role in improving the clinical manifestation of ARDS, alleviating the inflammatory condition of the lungs, and reducing the TNF-alpha level in the BALF and intestine homogenate, therefore they may be useful adjuvants in the treatment of ARDS.