Effect of bethanechol treatment on colon mucosal thickness and expression of matrix metalloproteinase genes. A. Representative H&E-stained normal colon mucosa from control and bethanechol-treated mice. Size bars represent 100 microns. B. Intestinal mucosal thickness in tissue from control and bethanechol-treated mice. C. Expression of Mmp mRNAs in normal proximal colon mucosa from each treatment group. D. Expression of Mmp mRNAs in tumors from each treatment group. QPCR was performed as described in Materials and Methods. Results are expressed as mean ± SE from 5 samples from each group. *P < 0.05, Student’s un-paired t-test.