Dietary fat-induced cell proliferation in the small intestine, analyzed by immunohistochemistry. Immunohistochemistry was performed on distal small intestinal sections of C57BL/6J mice fed a low-fat or high-fat diet using Ki67-specific antibodies. Besides the villus length (A) and total number of villus cells (B), also the number of Ki67-positive cells per villus (C) were determined. Per mouse, 15 villi were counted and the mean values were calculated. * p < 0.05, # p = 0.07. LF = low-fat diet, HF = high-fat diet.