In support of our earlier finding that the susceptibility of nitrergic myenteric neurons to experimentally induced diabetes is strictly regional [9], the present study provides evidence of gut segment-specific diabetes-related induction of the endogenous HO system and also the intestinal region-dependent enhanced colocalization of HO1 and HO2 with nNOS in myenteric neurons. This evidence concerns the gene HMOX1 and diabetes mellitus.