Surface hydrophobicity is increased in the ileum and proximal colon of cystic fibrosis mice

Patients with cystic fibrosis (CF) have abnormal concentrations and composi tion of electrolytes and macromolecules in gastrointestinal secretions. Suc h alterations could change intestinal surface properties, such as surface h ydrophobicity, and may influence the adhesion of macromolecules, bacteria, or microbial toxins to the intestinal surface. The objective of this study was to compare the surface hydrophobicity of the gastrointestinal tract in wild type and CF mice. We used axisymmetric drop shape analysis-contact dia meter to determine surface hydrophobicity by measuring contact angles of se ssile water droplets placed onto epithelial surfaces. In wild type mice, th ere were no differences in contact angles between the duodenum, upper jejun um, lower jejunum, and ileum. The contact angle of the gastric mucosa was l ower than the rest of the gastrointestinal tract. Contact angles of the pro ximal colon and distal colon were both higher than that of the gastric muco sa and those of the small intestinal sections. In CF mice, contact angles a long the gastrointestinal tract followed the same pattern as in wild type m ice. However, contact angles in the ileum and proximal colon of CF mice wer e greater than those from wild type mice. This study of the murine intestin e showed regional differences in surface hydrophobicity comparable to those observed in other mammalian species. In addition, we showed that the ileum and proximal colon of CF mice were more hydrophobic than the corresponding segments in wild type mice. These observations are of potential clinical r elevance because patients with CF exhibit clinical manifestations of gastro intestinal disease primarily in the ileum and proximal colon.