TLR4 expression on pancreatic islet beta cell of septic rat and its significance / 中华急诊医学杂志

ABSTRACT

Objective To investigate the Toll like receptor-4 (TLR4) expression on pancreatic islet beta-cell of septic rat and its effects on glucose regulation.Methods SD male septic rats were made with LPS intra-abdominal injection in a dose of 5 mg/kg body weight and it repeated once 3 h later.Rats were randomly (random number) divided into four groups randomly (n =5 in each)normal control group,LPS group,LPS antibody group and PLS with LPS antibody group.The expression and protein level of TLR4 were measured by RT-PCR,Western-blot and immunochemistry analysis respectively.IVGTT (intra-venous glucose tolerant test) was used to measure the glucose and insulin levels 6 hours after LPS administration and as well as in control group,and then their AUC were calculated.Results The TLR4 protein and mRNA expressed on pancreatic islet beta-cell of normal rat were significantly up-regulated 6 hours after LPS administration,while its up-regulation could be inhibited when LPS antibody was used in advance (P ＜ 0.01).Rat blood glucose levels were higher at 10,30,60 and 120 min in LPS group and insulin levels were lower at 30,60,120 min compared with normal control (P ＜ 0.01).LPS antibody improved the insulin secretion and then blood glucose level distinctly decreased during 30-120 min period after LPS challenge proved by IVGTT test.Conclusions TLR4 expression up-regulated on pancreatic islet beta-cell of septic rat and LPS-TLR4 system might be a mechanism of stress hyperglycemia genesis.