Abstract:
OBJECTIVE To investigate the effects of Ghrelin receptor antagonist on regulation of liver function and protection of vascular function in diabetic rats and its mechanism.
METHODS Using a high-fat diet combined with streptozotocin(STZ) in SD rats to construct a rat model of diabetes.Body weight and fasting blood glucose(FBG) were measured weekly after injection of STZ for 3 weeks.The degree of liver injury in each group was evaluated by HE staining.The levels of liver function related indexes in the serum of each group were analyzed by ELISA.HE staining was used to measure the area of neointimal and media of the internal carotid artery, and the ratio of intimal area to medium area(I/M) was calculated.Immunohistochemistry (IHC) staining were performed to evaluate the number and location of various cytokines.The expressions of IKKa and p-IKKa protein in liver tissue and internal carotid artery of each group were analyzed by Western blotting.The ratio of NF-κB, IKKa and p-IKKa mRNA was analyzed by RT-PCR.
RESULTS Compared with the control group, the blood glucose concentration and body weight of rats in model group were significantly increased, the liver cells were significantly damaged, and the liver function indexes were significantly increased, and the carotid intima was thickened and the expression of inflammatory factors intercellular cell adhesion molecule-1(ICAM1) and osteopontin(OPN) was significantly increased, while the expression of endothelial nitric oxide synthase(eNOS) was decreased, and the phosphorylation of IKKa in liver tissue and internal carotid artery was significantly enhanced.However, Ghrelin receptor antagonist treatment significantly reduced the blood glucose concentration and body weight of diabetic rats, weakened the liver damage, reduced the intimal thickness of the internal carotid artery and the expression of inflammatory factors ICAM1 and OPN, increased the expression of eNOS, and decreased the activation of NF-κB in liver and internal carotid artery.
CONCLUSION Ghrelin receptor antagonist plays a role in the regulation of liver function and vascular function in diabetic rats by promoting the activation of NF-κB.