Effects of combined exposure of arsenic and high-fat diet on serum adiponectin in mice / 中华地方病学杂志

ABSTRACT

Objective:To investigate the effects of combined exposure of arsenic and high-fat diet (HFD) on serum adiponectin in mice.Methods:According to the 2 × 3 factorial design, a total of 90 male C57BL/6 mice were randomly divided into 6 groups using random number table method based on body weight (16-22 g) standard diet (STD) control group, STD+ 5 mg/L arsenic group, STD+ 50 mg/L arsenic group, HFD control group, HFD+ 5 mg/L arsenic group and HFD+ 50 mg/L arsenic group. There were 15 mice in each group, and sodium arsenite (NaAsO 2) was added to the drinking water. Mice were accessed freely to water and fed ad libitum. After 17 weeks, urine samples, fasting blood samples and adipose tissue were collected. Urinary arsenic was determined by atomic fluorescence. Blood glucose meter was used to measure blood glucose. Levels of blood lipid contents, including serum triglyceride (TG), total cholesterol (TC), and high density lipoprotein cholesterol (HDL)-c, were examined by kit enzymatic method. Levels of insulin, total adiponectin and high molecular weight (HMW) adiponectin were examined by enzyme-linked immunosorbent assay. Results:There was no interaction between arsenic exposure and HFD on the effects of blood glucose and blood lipids ( P > 0.05). There was an interaction between these two factors on serum insulin and total adiponectin ( P < 0.05). HFD can significantly increase blood glucose, serum TC levels ( P < 0.05), but not TG and HDL-c in mice ( P > 0.05). The levels of TG and HDL-c in STD+ 50 mg/L arsenic group were significantly decreased as compared to those of STD control group (mmol/L 0.72 ± 0.14 vs 0.88 ± 0.24, 0.67 ± 0.03 vs 0.80 ± 0.16, P < 0.05). Compared with STD control group, there was no significant difference in serum insulin level in HFD control group and STD+ 5 or 50 mg/L arsenic groups ( P > 0.05), but insulin levels in HFD+ 5 or 50 mg/L arsenic groups were significantly decreased (mU/L 14.71 ± 4.16 vs 11.42 ± 0.78, 11.52 ± 1.53, P < 0.05). Compared with STD control group, serum total adiponectin, HMW adiponectin levels, and the ratio of HMW adiponectin to total adiponectin were significantly reduced in HFD control group and STD+ 5 or 50 mg/L arsenic groups ( P < 0.05). In HFD+ 5 mg/L arsenic group, the above indexes of adiponectin were significantly higher than those of the HFD control group ( P < 0.05). In STD groups, an inverse relationship was observed between log transformed urinary total arsenic concentrations and serum levels of total adiponectin and HMW partial correlation coefficient ( r=- 0.549,-0.608, P < 0.01). Conclusions:Both arsenic exposure and HFD can alter glucose and lipid metabolism in mice, but their manifestations are different. Arsenic exposure and HFD can synergistically reduce serum insulin levels, and have an antagonism on serum adiponectin.