Abstract: Objective To study the relationships among leptin, leptin receptor (OB-R) gene in arcuate nucleus and type 2 diabetes mellitus, and the effect of acupuncture on them. Methods Obese rats due to diet were injected in abdomen with small dosage streptozotocin to induce type 2 diabetes mellitus model, and were divided into acupuncture, glibenclamide and model group. Normal rats were in control. After treatment for 4 weeks, fasting blood sugar (FBS), fasting insulin (FINS), leptin, OB-R mRNA expression in arcuate nucleus were evaluated. Height, weight were measured and Lee's index were calculated before and after treatment. Results The FBS and FINS were higher in model group ［(15.79±1.87) mmol/L, (37.20±3.92) mIU/L］ than in control ［(5.16±0.13) mmol/L, (23.57±1.63) mIU/L］, but decreased in acupuncture group ［(5.46±0.20) mmol/L, (20.87±1.80) mIU/L］ and glibenclamide group ［(5.26±0.13) mmol/L, (28.10±1.86) mIU/L］. Leptin was lower in model ［(0.95±0.15) ng/ml］ than in control ［(1.32±0.15) ng/ml］, but was higher in glibenclamide group ［(1.83±0.23) ng/ml］ than in control. Weight and Lee's index decreased in model, acupuncture and glibenclamide groups after treatment. OB-R mRNA expression in arcuate nucleus in model wasn't different from control, acupuncture or glibenclamide group, nor between acupuncture and control, but was lower in glibenclamide group than in control. Conclusion Leptin decreased in type 2 diabetes mellitus rats when they became thin. Leptin resistance appears when treated with glibenclamide. Acupuncture may improve the OB-R mRNA expression in arcuate nucleus to some extent.

Key words: type 2 diabetes mellitus, leptin, leptin receptor, arcuate nucleus, gene, acupuncture, rats