ABSTRACT
Objective To investgate the effects of exenatide on islet β-cell function, insulin sensitivity and glucose-lipid metabolism in insulin resistant rats induced by high-fat-chow. Methods High fat-fed rats were treated with exenatide for 6 weeks. The insulin sensitivity, islet β-cell function and glucose lipid metabolism in awake rats were evaluated by intravenous glucose tolerance test (IVGTT), insulin tolerance test (ITT) and hyperinsulinemic-euglycemic clamp technique combined with 3-[3H] glucose as a tracer. In addition, plasma adiponectin level was measured by ELISA. Results Lee′s index and levels of plasma free fatty acids (FFA), triglyceride and total cholesterol were significantly reduced in high fat-fed rats after exenatide treatment for 6 weeks (all P＜0.01). In these rats exenatide also improved IVGTT and ITT, and increased the level of insulin secretion, especially when a high dose was given. In addition, plasma adiponectin level was also significantly increased in the group with high dose exenatide (HFH, P＜0.01). During the clamp steady-state, there were significant increases in plasma FFA and insulin and significant decreases in glucose infusion rate (GIR), glucose disposal rate (GRd) in high-fat group (HF) compared to control group (NC, all P＜0.01). The suppressive effect of insulin on hepatic glucose production (HGP) was significantly blunted (only 26%) in HF group. In HFH group, plasma insulin and FFA levels were significantly decreased (both P＜0.01), GIR and GRd were significantly increased (both all P＜0.01), and HGP was suppressed by 72%. Conclusion It is possible that exenatide pretreatment ameliorates high-fat induced insulin resistance by promoting β-cell insulin secretion, elevating adiponectin level, and improving glucose-lipid metabolism.
ABSTRACT
Objective To establish a multiple PCR method that can be used to spontaneously detect five kinds ofpathogens such as NG,MH,MG,CT and UU.Method With the fluorescence-quantitative PCR technique in conjunction with another detection technique as the golden standard,evaluation was conducted on the sensitivity,specificity,accuracy and repeatability on the detection of 5 kinds of STD pathogens using single-tube multiplex PCR.Result The sensitivity,specificity and match rate of the method ale 10-9fg/μl,100%,97.8%respectively,and the repeatability of 5 continuous days of 20 clinical specimens is good.Conclusion Single-tube multiplex PCR technique provides a new method to detect 5 kinds of STD pathogens.
ABSTRACT
Objective To investigate the effects of exendin-4 (exenatide) on insulin sensitivity and adipocytokine in high-fat-fed rats. Methods Rats were divided randomly into normal-chow group (NC), high-fat group (HF) and high-fat+exendin treated group (HE). HE rats were given exenatide (2 μg/kg) twice daily for 6 wk. The insulin sensitivity was evaluated by intravenous insulin tolerance test (IVITT). Insulin-stimulated changes in insulin signal transduction, visfatin and adiponectin mRNA expressions as well as their plasma levels were also observed in these rats. Results Plasma free fatty acids (FFA), triglyceride (TG), total cholesterol (TC) levels were significantly reduced after exenatide treatment (in HE rats all P<0.01). And IVITT parameters were also improved in these rats. Insulin-stimulated IRS-1 tyrosine phosphorylation was slightly increased in exenatide-treated rats as compared with HF rats (P<0.05). In addition,plasma visfatin level was significantly reduced in HF and HE groups as compared with controls (P<0.05 and P<0.01). The adiponectin mRNA expression in adipose tissues and circulating adiponectin level were significantly elevated in exenatide-treated rats as compared with untreated rats and controls (P<0.01). Conclusions Chronic exenatide treatment improves insulin resistance in high-fat-fed rats, and the changes of IRS-1 tyrosine phosphorylation and adiponectin may be related to the role of exenatide in elevating insulin sensitivity