Objective To investigate the expression of aquaporin-1( AQP-1) in pleural mesothelial cells ( PMCs) and the influence of glucose thereupon. Methods Rat PMCs were isolated, cultured, and divided into two groups, ie. a glucose group, cultured with glucose of different concentrations for 24 hours,and a control group, cultured in D-MEM/ F-12 medium. The 100 mmol / L glucose group was administered at the time points of 6, 12, 18, and 24 hours respectively. RT-PCR and Western blotting were used to analyze the mRNA and protein expression of AQP-1. Results The absorbance values of AQP-1 protein expression were 54. 02 ±4. 61, 127. 84 ±9. 41, and 231. 62 ±22. 63, respectively in the PMCs treated with glucose of the concentrations of 50, 100, and 200 mmol / L, all significantly higher than those in the control group( 22. 45 ±2. 16, all P lt; 0. 01) . The absorbance values of AQP-1 protein expression were 24. 68 ±2. 56, 58. 68 ±3. 67, 89. 61 ±6. 62, and 113. 41 ±7. 65 in the PMCs treated with glucose of the concentration of 100 mmol / L after 6, 12, 18, and 24 hours, all significantly higher than those in the control group ( 11. 81 ±1. 45, P lt;0. 01) .Conclusions Glucose induces the expression of AQP-1 mRNA and protein. AQP-1 participates in the pleural fluid formation.
Objective To investigate the effects of expression of TNFα mRNA on glucose uptake in both the liver and skeletal muscle after endotoxemia. Methods In the mice with intraperitoneal injection of lipopolysaccharide (LPS), the changes of TNFα level of plasma and uptake of 2-deoxyglucose (2-DG) in the isolated soleus muscle and hepatic tissues were determined, then the reinstatement of glucose uptake by injecting TNF-McAb for 3 days was also observed. In addition, changes of TNFα mRNA expression of liver were evaluated. Results The expression of TNFα mRNA in the liver showed markedly increased in the first 3 hours post endotoxemia and remaind high for 3 days, and the plasma TNFα level paralleled with TNFα mRNA expression of liver also was elevated. The basal uptake of 2-DG both in muscle and liver were markedly increased, but the stimulated 2-DG uptake with insulin was greatly reduced as compared with the control. In addition, these abnormalities of 2-DG uptake can be partially corrected by neutralization of the circulatory TNFα by administration of TNF-McAb. Conclusion The disorders of glucose uptake of the liver and the muscle due to the overexpression of TNFα mRNA and elevated circulatory TNFα level may be the mechanism of insulin resistance after endotoxemia.
Objective To investigate the effect of glucagon-like peptide-1(GLP-1) on impaired glucose tolerance due to stress postoperatively. Methods The rats were allocated randomly to one of three groups, group Ⅰ was subdivided into group Ⅰg which received an intravenous glucose load (0.5 g/kg glucose), and group Ⅰglp which received the same glucose load with GLP-1 (0.3 nmol/kg) during intravenous glucose tolerance test (IVGTT). Rats in group Ⅱg and group Ⅱglp in group Ⅱ were infused respectively the same intravenous glucose tolerance test as group Ⅰ on the first, third and fifth day after 65% liver resection. And rats in group Ⅲ were injected the same glucose load with GLP-1 (0.45 nmol/kg) during IVGTT on the first day after hepatectomy. The peak glucose levels, glucose levels at 30 minutes and the area under the curve (AUC0-30) were investigated among groups. Results The peak glucose levels, glucose levels at 30 minutes and AUC0-30 were significantly lower in group Ⅰglp than those in group Ⅰg. And the values were significantly higher in group Ⅱg than those in group Ⅰg on the first, third and fifth day after operation. There was no significant difference between group Ⅱglp and group Ⅱg in the peak glucose levels on the first day after liver resection, but the peak glucose levels and AUC0-30 were significantly lower in group Ⅲ than those in group Ⅱg and group Ⅱglp, and the glucose levels at 30 minutes were significantly lower in group Ⅲ than those in group Ⅱg too on the first day. The peak glucose levels were significantly lower in group Ⅱglpthan those in group Ⅱg on the third and fifth postoperative day and in group Ⅱglp on the first day too, and the glucose levels at 30 minutes and AUC0-30 were also significantly lower in group Ⅱglp than those in group Ⅱg, but they were similar between group Ⅱglp and group Ⅰg. Conclusion Glucose intolerance is a feature of stress after hepatectomy, and GLP-1, injected in conjunction with the IVGTT, increased the clearance of glucose. The contribution of GLP-1 to reducing blood glucose was decreased significantly at early phase postoperatively, but its action was enhanced by the way of dosage dependence. The action of GLP-1 was enhanced with the degree of stress reduction and then returned to normal.
ObjectiveTo study the effects of Ghrelin for glucose metabolism and insulin sensitivity of L6 rat myoblasts in palmitic acid induced, and to explore its possible mechanisms. MethodsThe L6 rat myoblasts were cultured until differentiation, then using palmitic acid(0.3 mmol/L) for 16 hours. The experimental group was treated with different doses of Ghrelin(1, 10, and 100 nmol/L) for 8 hours, then the glucose uptake was detected by using glucose oxidase peroxidase method(GOD-POD), the cell membrane glucose transporter 4(GLUT-4) protein staining was observated under confocal microscopy, and the expressions of total protein kinase B(Akt), phosphorylated protein kinase B(pAkt), total glycogen synthase kinase-3β(GSK-3β), and phosphorylated glycogen synthase kinase-3β(pGSK-3β) were detected by using immunoblotting(Western blot). ResultsGhrelin enhanced the glucose uptake of L6 rat myoblasts with insulin resistance, the cell membrane Glut-4 stain was deepen, the expressions of pAkt and pGSK-3βprotein increased, and this effect could be PI3K blocker(LY294002) eliminated. ConclusionGhrelin promotes the glucose uptake of L6 rat myoblasts through PI3K/Akt/GSK-3βsignaling pathway, so as to improve the sensitivity of insulin in L6 rats muscle cells.
Objective To observe the different effect such as high concentration of glucose and high concentration of insulin on GLUT1 of Rabbit Retinal Muuml;ller Cell in vitro. Methods Rabbit retinal Muuml;ller cells were cultured in vitro with suspended constitution，which were divided as the following groups: common control group，high glucose group，insulin group，high glucose combined insulin group. Laser confocal microscope combined with immunocytochemical and fluorescence staining method to quantitatively analyze the expression condition of GLUT1. Results The expression of GLUT1 has been enhanced obviously by high glucose and high insulin，which locates mainly in the cytoplasm that near to the nucleus. Conclusion Rabbit retinal Muuml;ller cells can express GLUT1，and the expression of GLUT1 can be reinforced by high glucose and high insulin. （Chin J Ocul Fundus Dis，2008，24：265-267）
Objective To observe the effects of high concentr at ion glucose on the calcium-activated potassium channel of rabbits′ retinal Müller cells. Methods The rabbits′retinal Müller cells were cultured in vitro under the condition of high concentration glucose, and identified by immunohistochemical staining and transmission electron microscopy. Patch-clamp technique was used to observe the changes of the calcium-activated potassium channel of retinal Müller cells caused by high concentration glucose at different time.Results High concentration glucose could inhibit the calcium-activated potassium channel of cultured retinal Müller cells in a time-dependent manner. Conclusion High concentration glucose may reduce the biological functions of Müller cells by inhibiting calcium-activated potassium channel. (Chin J Ocul Fundus Dis，2003，19：164-167)
Objective To assess the differences between a glucose meter and autoanalyzer at home and broad.Method MEDLINE, CNKI, FMJS, and CBM were searched electronically (1995 to May, 2008). The statistical analysisof included studies was performed according to the Cochrane systematic reviews method. Result Twenty four studies, including 11 English records and 19 Chinese records involving 4 963 specimens, were included in this study. Meta-analysis showed us the blood glucose values of Abbott, Roche, and Johnson abroad subgroups are higher than the laboratory method, and their WMD (95%CI) are 0.57 (0.34,0.80), 0.43 (0.04,0.81), 0.41 (0.11,0.71). The blood glucose values of the Abbot and Roche domestic subgroups are comparable to the laboratory method [WMD= 0.60, 95%CI (– 0.79, 1.99); WMD= – 0.13, 95%CI (– 0.56, 0.29)]. The blood glucose value of the Johnson domestic subgroup is lower than laboratory method [WMD= – 0.95, 95%CI (– 1.42, – 0.48)]. Conclusion The results of the abroad studies are relatively consistent, and the blood glucose values of all abroad subgroups are higher than laboratory method. The domestic studies are different because of other factors.
ObjectiveTo observe and analyze the correlation between time within target glucose range (TIR) and hemoglobin A1c (HbA1c) and the risk of diabetic retinopathy (DR). MethodsA retrospective clinical study. From March 2020 to August 2021, 91 patients with type 2 diabetes mellitus (T2DM) who were hospitalized in Department of Endocrinology and Metabolic Diseases, Affiliated Hospital of Weifang Medical University, were included in the study. All patients underwent Oburg's no-dilatation ultra-wide-angle laser scan ophthalmoscopy, HbA1c and continuous glucose monitoring (CGM) examinations. According to the examination results and combined with the clinical diagnostic criteria of DR, the patients were divided into non-DR (NDR) group and DR group, with 50 and 41 cases respectively. The retrospective CGM system was used to monitor the subcutaneous interstitial fluid glucose for 7 to 14 consecutive days, and the TIR was calculated. Binary logistic regression was used to analyze the correlation between TIR, HbAlc and DR in patients with T2DM0. At the same time, a new indicator was generated, the predicted probability value (PRE_1), which was generated to represent the combined indicator of TIR and HbA1c in predicting the occurrence of DR. The receiver operating characteristic curve (ROC curve) was used to analyze the value of TIR, HbAlc and PRE_1 in predicting the occurrence of DR. ResultsThe TIR of patients in the NDR group and DR group were (81.58±15.51)% and (67.27±22.09)%, respectively, and HbA1c were (8.03±2.16)% and (9.01±2.01)%, respectively. The differences in TIR and HbA1c between the two groups of patients were statistically significant (t=3.501,－2.208; P=0.001, 0.030). The results of binary logistic regression analysis showed that TIR, HbA1c and DR were significantly correlated (odds ratio=0.960, 1.254; P=0.002, 0.036). ROC curve analysis results showed that the area under the ROC curve (AUC) of TIR, HbA1c and PRE_1 predicting the risk of DR were 0.704, 0.668, and 0.707, respectively [95% confidence interval (CI) 0.597-0.812, P=0.001; 95%CI 0.558-0.778, P=0.006; 95%CI 0.602-0.798, P=0.001]. There was no statistically significant difference between TIR, HbA1c and PRE_1 predicting the AUC of DR risk (P>0.05). The linear equation between HbAlc and TIR was HbAlc (%) = 11.37－0.04×TIR (%). ConclusionsTIR and HbA1c are both related to DR and can predict the risk of DR. The combined use of the two does not improve the predictive value of DR. There is a linear correlation between TIR and HbAlc.
ObjectiveTo investigate the prevalence of impaired glucose regulation (IGR) and IGR combined with cardiovascular risk factors in rural areas of Chengdu City. MethodsFrom February to October 2010, we randomly sampled 1 016 patients in a rural community 100 kilometers away from the city center as the study subjects. The investigation was carried out by using questionnaire survey, physical examination and laboratory tests. The standard 75 g oral glucose tolerance test was used. ResultsA total of 1 016 subjects were investigated, among whom there were 431 males and 585 females with an average age of 56 years old. Of these subjects, 333 were diagnosed to have IGR with a rate of 32.77% (333/1 016). The age-adjusted standardized prevalence of pre-diabetes in rural areas in Chengdu was 32.52% (336/1 016), and the male and female prevalence were respectively 30.63% (132/431) and 34.36% (201/585) without significant difference (χ2=1.569，P=0.210). Impaired glucose tolerance (IGT) was the most common type of glycometabolism abnormality. Women had a significantly higher prevalence of IGT than men. In IGR population, major cardiovascular risk factors were overweight and obesity (40.8%), high low density lipoprotein cholesterol (38.4%), high triglyceride (30.3%), hypertension (23.7%), smoking (24.3%), and drinking alcohol (23.7%). The stratified analysis showed that the prevalence of overweight, obesity and low high density lipoprotein cholesterol in female was significantly higher than that in males, while the prevalence of smoking and drinking alcohol was significantly higher in males. ConclusionIn rural areas, the prevalence of pre-diabetes is high and complicated with multiple cardiovascular risk factors.
Objective To explore the effect of ghrelin on insulin secretion and expression of glucose transporter protein-2 （Glut-2） in isolated pancreas of rats. Methods Twenty five Wistar rats were randomly devided into normal control group （NC group）， high concentration of glucose group （HCG group）， high concentration of glucose with high concentration of ghrelin group （10-8mol/L， HCG＋HCGh group）， medium concentration of ghrelin group（10-9mol/L， HCG＋MCGh group）， and low concentration of ghrelin group （10-10mol/L， HCG＋LCGh group） with 5 rats in each group. The rat isolated pancreas perfusion models were established firstly， then from the distal end of abdominal aortas， the models were perfused with low concentration of glucose （5.5mmol/L）， high concentration of glucose （33.3mmol/L） or high concentration of glucose added with different concentrations of ghrelin. Levels of insulin outflowed from portal vein were tested by ELISA method， expression levels of Glut-2 protein were tested by immunohistochemical method，and ultrastructure changes of islet β cell were observed under the transmission electron microscope. Results There were no significant difference on levels of fasting blood glucose （FBG）， fasting insulins （FINS）， homeostasis model of assess-ment for insulin resistence index （HOMA-IR）， and homeostasis model of assessment for pancreatic β cell function （HOMA-β），（P＞0.05）. There were no significant difference on insulin levels of effluent from portal vein of 5 groups （P＞0.05） when isolated pancreas perfused with 5.5mmol/L glucose， while had 2 secretion peaks in 3min and 10-12min after 33.3 mmol/L glucose perfusion， where HCG＋HCGh group at the top. The mean density value of Glut-2 protein in NC group was higher than that of other 4 groups （P＜0.05）. The results of transmission electron microscopy showed that apoptosis was lighter in NC group than that of other 4 groups， and apoptosis of HCG＋HCGh group was lighter than that of HCG＋MCGh group and HCG＋LCGh group. Conclusions In isolated pancreas of rats， ghrelin promotes high concentration of glucose-stimulated insulin secretion， decreases expression of Glut-2 protein， and protects the islet β cell.