Obstructive Jaundice Alters LFA-1α 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-1α 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-1α staining the on jejunum between grouP1 (CBDL) and grouP3 (sham control) (P < 0.05). However, the LFA-1α staining on the ileum in grouP1 (CBDL) significantly decreased when compared with grouP3 (sham control) (P = 0.008). With oral glutamine administration (0.2 g/kg body weight, once daily), LFA-1α staining on the ileum was significantly restored in grouP2 (CBDL + G). In conclusion, obstructive jaundice for one week down-regulates LFA-1α expression on rat ileum. With oral glutamine administration, such down-regulation of LFA-1α expression on rat ileum can be restored. Such a phenomenon is intriguing and deserves further evaluation and elucidation.