THORACIC DUCT LIGATION IN THE RAT ATTENUATES LUNG INJURIES IN ACUTE PANCREATITIS

Abstract

In acute pancreatitis (AP), inflammatorycells and products disseminated in abdominallymph and blood induce systemic inflammation.Interruption of abdominal lymph flow, andthereby reduction of lymphatic dissemination,could alter the course of the disease. Therefore,we investigated whether thoracic duct ligation(TDL) in a rat model of cerulein-induced APresults in reduced lung damage as a markerfor reduction of systemic disseminationthrough the lymphatic system. Thirty-fourmale rats were assigned to TDL (TDL-rats,n=8), AP (AP-rats, n=8), TDL+AP (TDL+APrats,n=9) or sham TDL (Ctr-rats, n=9)groups. TDL and sham TDL were establishedfirst. Two days later, AP was induced in APandTDL+AP-rats by a series of subcutaneousinjections of cerulein. Vehicle was injected inthe same manner in Ctr- and TDL-rats ascontrols. Rats were sacrificed six hours afterthe end of the serial injections. Histologicalexamination showed that AP-induced damageto the pancreas and ileum were similar inAP- and TDL+AP-rats whereas lung damagewas less severe in TDL+AP-rats than inAP-rats. Assays demonstrated that: hepaticand pulmonary myeloperoxidase activitieswere increased in AP-rats but not in theTDL+AP-rats; more Il-6 was found in AP-ratthan TDL+AP-rat lungs; and lung-lavagefluid from AP-rats yielded more angiopoietin-2than TDL+AP-rats. In conclusion, prior TDL in the rat attenuates lung damage in acutepancreatitis.