Effects of polychlorinated biphenyl 118 on the insulin sensitivity in Wistar rats

Abstract

Objective To investigate the effects of polychlorinated biphenyl (PCB)118 on the insulin sensitivity in rats. Methods Forty male Wistar rats were randomly divided into 4 groups: solvent control group, low dose, medium dose, high dose group (PCB118 0, 10, 100, 1000 μg·kg-1·d-1), respectively, with PCB118 intraperitoneally for five consecutive days per week. After 13 weeks, an intraperitoneal glucose tolerance test (IPGTT) was performed, and the ratio of increment insulin to glucose concentration at 30 min after the glucose loaded (ΔI30/ΔG30), area under the curve (AUC) of glucose (AUCg), AUC of insulin (AUCi), AUCi/AUCg and homeostasis model assessment of insulin resistance (HOMA-IR) were calculated. One-way analysis of variance (ANOVA) was used for data analysis. Results Compared with the controls, fasting insulin levels and insulin and blood glucose levels at IPGTT 30 min were significantly increased in all the PCB118-treated groups (fasting insulin levels: (19.0±7.1), (18.5±3.1), (22.1±1.2) vs (10.0±3.6) mU/L; insulin levels at IPGTT 30 min: (55.0±1.9), (55.0±2.4), (72.3±1.0) vs (25.7±1.3) mU/L; blood glucose levels at IPGTT 30 min: (22.3±2.4), (19.87±1.89), (21.90±2.88) vs (17.08±1.35) mmol/L, F values were 3.622, 8.798 and 7.024, respectively, all P 0.05). Conclusion Continuous exposure to a low dose of PCB118 could reduce insulin sensitivity in rats. Key words: Diabetes mellitus, type 2; Polychlorinated biphenyl; Insulin sensitivity; Rats