Objective: Short-term hypoglycemic effects of single dose voglibose and nateglinide were compared after sucrose loading in spontaneously diabetic Otsuka Long-Evans Tokushima fatty (OLETF) rats.
Materials and methods: After a 17-h fasting period, the animals received 0.06 mg/kg of voglibose (VOG group, n = 6), 50 mg/kg of nateglinide (NAT group, n = 6), or 0.5% methyl cellulose (control group, n = 6), immediately followed by 2.5 g/kg of sucrose.
Results: Compared to control group values, glucose levels after sucrose loading were significantly decreased in the portal blood in the VOG group and in the peripheral blood in the NAT and VOG groups. The portal glucose AUC0-120 min was significantly lower in the VOG group than in the control and NAT groups, whereas the peripheral glucose AUC0-120 min was significantly lower in the VOG and NAT groups than in the control group. Portal insulin levels in the VOG group were significantly decreased compared to the control group. However, portal insulin levels in the NAT group were acutely increased, peaking 15 min after sucrose loading. Portal FFA levels were decreased in the NAT group 15, 30, and 60 min after sucrose loading; no FFA reductions were seen in the VOG group.
Conclusions: Although both drugs produced similar hypoglycemic effects after sucrose loading in the peripheral blood, these drugs generated vastly different results in portal blood. Reduced FFA in the portal blood, observed after single administration of nateglinide, may have a favorable impact not only on glucose metabolism but also on lipid metabolism.