Protective effect of glucocorticoidson on rat lung in a rat model of oleic acid-induced acute respiratory distress syndrome lung injury / 中国综合临床

ABSTRACT

Objective To investigate the effect of glucocorticoid on rat lung in a rat model of oleic acid-induced acute respiratory distress syndrome(ARDS)lung injury. Methods Sixty SPF level of healthy male Wistar rats were randomly divided into normal control group(group A),oleic acid model group(group B)and oleic acid and Methylprednisolone group(group C),and each group with 20 cases rats. ARDS model rats were established by injection with oleic acid(0. 14 ml/ kg)intravenously. Twelve hours after injection,aterial blood was drawn for blood gas analysis of blood oxygen partial pressure in order to confirm that acute lung injury model was successful. Then the rats in group C were treated with injection of Methylprednisolone( 4 mg/ kg) intravenously,once a day,from the 1st to 7th day. The rats in A and B groups were given saline(4 ml/ kg). Five rats in each group were randomly sacrificed on the1st,7th,14th,28th day respectively. The left lung of all rats was underwent bronchoalveolar lavage after weighed. Bronchoalveolar lavage fluid( BALF)were obtained for detection of procollagen III(PCⅢ)concentrations with enzyme-linked immunosorbent assay( ELISA). Right lobe of lung specimens was used for histopathological examination. Results Compared with the group A,PaO2 in group B and C were decreased significantly(P 0. 05). The levels of PCⅢ concentrations of BALF in Group A,B and C group were(30. 61 ± 0. 52)μg/ L,(30. 14 ± 0. 41)μg/ L and(30. 71 ± 0. 74)μg/ L respectively on the first day,(29. 15 ± 0. 17)μg/ L,(34. 35 ± 0. 73)μg/ L and(31. 72 ± 0. 46)μg/ L respectively at the 7th day,(30. 23 ± 0. 41)μg/ L, (38. 61 ± 1. 21)μg/ L and(33. 32 ± 0. 57)μg/ L respectively at 14th day and(31. 12 ± 0. 22)μg/ L,(37. 53 ± 2. 46)μg/ L and(34. 45 ± 0. 27)μg/ L respectively at 28th day. Levels of PCⅢ concentrations of BALF at 7th, 14th and 28th day time point in group B and C were decreased in comparison of A group(P < 0. 05),and there was significant difference between B and C group(P < 0. 01). Conclusion A treatment with Methylprednisolone may be useful in inhibiting pulmonary fibrosis in the process of ARDS in rats.