Obstructive jaundice alters LFA-1alpha expression in rat small intestine.

Abstract

Translocation of bacteria and endotoxtin has long been documented in obstructive jaundice, and altered intestinal barrier function is considered to be one of the important mechanisms for this phenomenon. The regulation of gastrointestinal mucosal response to injury is thus of important clinical as well as biological relevance. Integrins play a critical role in enterocyte migration, which is essential to mucosal healing. This study is designed to evaluate the integrins status in obstructive jaundice. Male Sprague-Dawley rats (N = 37) were randomized to three groups. Group 1 (N = 12) underwent common bile duct ligation (CBDL), group 2 (N = 12) underwent common bile duct ligation with oral glutamine administration (CBDL + G), and group 3 (N = 13) underwent a sham operation (sham control). After seven days, segments of proximal jejunum and distal ileum were harvested, and cell surface immunohistochemical expression of LFA-1alpha and VLA-6 were evaluated and recorded. The staining intensities were graded on a scale of 0-4. Comparisons among the three groups were performed. There was no significant difference in VLA-6 staining on small intestine among the three groups (P > 0.05). There was also no significant difference in LFA-1alpha staining the on jejunum between group 1 (CBDL) and group 3 (sham control) (P > 0.05). However, the LFA-1alpha staining on the ileum in group 1 (CBDL) significantly decreased when compared with group 3 (sham control) (P = 0.008). With oral glutamine administration (0.2 g/kg body weight, once daily), LFA-1alpha staining on the ileum was significantly restored in group 2 (CBDL + G). In conclusion, obstructive jaundice for one week down-regulates LFA-1alpha expression on rat ileum. With oral glutamine administration, such down-regulation of LFA-1alpha expression on rat ileum can be restored. Such a phenomenon is intriguing and deserves further evaluation and elucidation.