Nicotinamide overload may play a role in the development of type 2 diabetes

Figure 5 Effects of aldehyde oxidase (AOX) inhibitors on plasma N¹-methylnicotinamide levels and glucose metabolism in rats. A and B: Plasma N¹-methylnicotinamide (NMN) levels 5 h after nicotinamide load (100 mg/kg, ip) in rats treated with or without AOX inhibitors tamoxifen (Tam, A) or olanzapine (Olan, B) (each group, n = 6). ^aP < 0.05 vs control, ^bP < 0.01 vs control; C: Liver AOX expression in rats with or without 7 wk tamoxifen treatment. The blot is representative of four independent experiments; D: Responses to a glucose tolerance test in rats after 9 wk treatment with tamoxifen with or without NMN (100 mg/kg per day) treatment in the last 2 wk. FBG: Fasting blood glucose; GTT (1 h): Blood glucose measured 1 h after glucose tolerance test. ^bP < 0.01 vs control. Bar graph indicates mean ± SD.