Salhy et al. [61] set up rat colitis models induced by trinitrobenzene sulfonic acid (TNBS) and found that, compared with the control group, the amount of PYY, CgA and pancreatic polypeptide-producing cells obviously decreased in the TNBS group, contrary to the number of serotonin and oxyntomodulin, as well as somatostatin-producing cells, significantly increased in the TNBS group. Here, GCG is linked to colitis.