The pulmonary inflammation and acute lung injury in endotoxin tolerant rats / 中国呼吸与危重监护杂志

ABSTRACT

Objective To investigate the endotoxemia initiated systemic and pulmonary inflammation and acute lung injury in endotoxin tolerant rats MethodsEndotoxi n tolerance (ET) models of SD rats were induced by four daily intraperitoneal in jections of 0 6 mg?kg -1 ?d -1 Escherichia coli LPS (serotype 055B5).Normal control (NC) rats received intraperitoneal injections of the sa me volume saline On the fifth day,rats were injected with high dose of LPS (6 mg/kg) to induce endotoxemia and lung inflammation Blood,left bronchoalveolar lavage fluid (BALF) and right lung tissue were collected before and 2,6,24,48 ,72 hours after the high dose injection of LPS (six rats for each time point) Cytological examination of blood and BALF and histopathological examination wer e performed Bromine methylphenol green was adopted for measurement of serum alb umin BALF albumin was measured by en z yme-linked immunosorbent assay (ELISA) and adjusted by the ratio to serum album in to evaluate the permeability of pulmonary microvascular Results The symptomes such as less activity,accelerated respiratory rate and weight loss in NC rats was not found in ET rats after the high dose injectio n of LPS BALF albumin as well as the ratio of BALF albumin to serum albumin in c reasedt 2 hours after injection of 6 mg/kg LPS and reached their zenith at 6 hou rs in NC rats,while no increase in ET rats In NC rats the blood white cell dif f erentiating shifted from lymphocyte to PMN,and PMN percentage of BALF also incr eased from (0 443?0 345)% to (8 000?2 896)% with its peak at 24 hours a fter the injection (P