Immunohistochemical analysis of the COX-2 marker in acute pulmonary injury in rats.

Abstract

Acute inflammatory response is one of the main defensive mechanisms of the lungs. This work tried to assess this response through an immunohistochemical analysis of rat lungs mechanically injured by open manipulation, analyzing the COX-2 inflammatory marker, in addition to performing a microscopic histological analysis using the hematoxylin and eosin stain. The correlation between this response and the degree of manipulation over different lengths of time and degrees of injury was also investigated. Sixteen rats were divided into four groups and subjected to anterior thoracotomy. The upper lobe of the right lung was compressed using a plastic Bulldog clamp for different time length according to group (5 minutes, 2 minutes, and three 10-second compressions with 10 second intervals). The control group was subjected to thoracotomy but their lungs were not compressed. The injured lobes were analyzed histologically and subjected to immunohistochemistry and the results were compared. There were no differences in the immunohistochemical patterns between the control and injured rats, but the histological patterns between them differed. In conclusion, the histological analysis shows that the degree of injury caused by clamping the pulmonary parenchyma increases as the time length of compression increases but this inflammatory response is not paralleled by modifications of the COX-2 marker at immunohistochemistry.