Fig 5. L-NAME but not D-NAME decreased iNOS expression of the intestinal mucosa, hepatic bacteria clearance, and IL-1β as well as TNF-α expression of the Kupffer cells in STZ-DM mice.

(A) STZ-DM mice demonstrated a significant increase of iNOS protein expression of the intestinal mucosa as compared with that in the WT group. L-NAME but not D-NAME supplementation decreased iNOS protein expression of the intestinal mucosa in STZ-DM mice. (B) L-NAME but not D-NAME feeding decreased the bacterial loads of liver in STZ-DM mice. STZ-DM mice were fed with an L-NAME (0.5 mg/ml) or D-NAME (0.5 mg/ml, as a control drug) in drinking water for one week. K. pneumoniae (1 × 10³ CFU, K2 serotype) were injected into the branch of superior mesenteric vein (SVC). The liver was collected, weighed and homogenized at 4 hr after the injection for bacterial culture. (C) STZ-DM mice demonstrated a significant increase of IL-1β and TNF-α expression of the Kupffer cells. L-NAME but not D-NAME supplementation markedly decreased diabetes-induced IL-1β and TNF-α mRNA expression of Kupffer cells in STZ-DM mice. STZ, streptozotocin; L-NAME, L-NG-Nitroarginine Methyl Ester; DM, diabetes mellitus; FOS, fructooligosaccharides; dLac, dead L. salivarius. *, P< 0.05; **, P< 0.01; ***, < 0.001. n = 6/group.