Effects of experimental wheat and corn gluten on liver tissue in rats: biochemical, histopathological, immunohistochemical and immunofluorescence methods

This study was aimed at determining the effects of wheat gluten, corn gluten and soybean meal, incorporated into feed as protein sources, on the hepatic tissue of rats, based on the investigation of histopathological parameters (degeneration, inflammation, biliary hyperplasia and fat droplets), immunohistochemical parameters (transglutaminase, gliadin, IgA, IgG, CD4 and CD8), and the serum levels of hepatic enzymes [(aspartate aminotransferase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH)]. Three groups, referred to as Wheat Group, Group Corn and Group Soybean, were established, and were given high levels of wheat gluten, corn gluten and soybean meal as protein sources in the feed, respectively. The study material comprised forty–eight 20–day–old female Sprague Dawley rats. In the group, which received dietary wheat gluten, the hepatic tissue presented with numerically higher histopathological and immunohistochemical parameters on day 45 of the study, and numerically higher histopathological parameters on day 165 of the study (P>0.05). On day 165 of the study, when compared to Groups Corn and Soybean, Group Wheat displayed a significantly different level of sensitivity to immunohistochemical parameters (transglutaminase, gliadin, IgA, IgG, CD4 and CD8). It was determined that gluten significantly reduced the activity of the liver enzymes LDH and AST. In result, it was ascertained that rats, not carrying the genes HLA–DQ2 and DQ8, when fed on a ration incorporated with a high level of wheat gluten, displayed slightly affected hepatic tissue histopathological parameters and significantly increased immunohistochemical parameters (transglutaminase, gliadin, IgA, IgG, CD4 and CD8).