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 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.
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 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 study the effects of hypoxic preconditioning on the glucose metabol ism of rat BMSCs and its underlying mechanism so as to provide the theoretical basis for the optimization of the stem-cell based therapy. Methods Density gradient centrifugation method was adopted to isolate rat BMSCs from neonatal SD rats (aged 1-3 days). BMSCs were cultured to 4th passage and divided into 4 groups based on different culture conditions: group A in normoxia condition for 24 hours, group B in 1% O2 for 24 hours, group C in 2-methoxyestradiol (20 μmol/L) for 24 hours before hypoxic preconditioning, and group D in hypoxia-inducible factor 1 (HIF-1) specific siRNA (50 μmol/L) for 12 hours before hypoxicpreconditioning. MTT method was appl ied to evaluate the prol iferation of BMSCs. Biochemical analyzer and Real-timefluorescent quantitative PCR were appl ied to detect the glucose uptake, lactate production, and HIF-1α mRNA and Glut-1mRNA levels of BMSCs. Results MTT showed that the absorbance (A) values were 387.67 ± 58.92, 322.50 ± 50.60, 297.00 ± 53.00, and 286.00 ± 41.00 in groups A, B, C, and D, respectively, showing no significant difference among 4 groups (P gt; 0.05). The levels of glucose uptake and lactate production were higher in group B than in groups A, C, and D, showing significant differences (P lt; 0.05); the levels of groups C and D were higher than those of group A, but showing no significant difference (P gt; 0.05). The mRNA expressions of HIF-1α and Glut-1 elevated significantly in group B when compared with those in group A (P lt; 0.05); groups C and D were significantly lower than group B (P lt; 0.05) and were significantly higher than group A (P lt; 0.05). Conclusion Hypoxic preconditioning can stimulate the glucose uptake and metabol ism of rat BMSCs, whose mechanism is probably related to up-regulating the mRNA expressions of HIF-1α and Glut-1.
Objective To explore the relationship between obesity and the three targets including blood pressure, glucose, and lipid. Methods A total of 181 adult Tibetans who underwent physical examination between March and September 2015 at Xigaze People's Hospital were enrolled in this study. Their obesity degrees were assessed with body mass index (BMI) and waist circumference (WC) respectively. The levels of blood pressure, glucose, and lipid were compared at the different levels of BMI or WC. Results The incidence of systematic obesity and central obesity in these adults were 57.5% and 79.0%, respectively. Compared the overweight group with the normal BMI group, the systolic pressure and diastolic pressure of the former were 9.26 mm Hg (1 mm Hg=0.133 kPa) [95% confidence interval (CI) (3.46, 15.07) mm Hg, P=0.002] and 7.76 mm Hg [95%CI (3.96, 11.57) mm Hg, P<0.001] higher, respectively. Similarly, the systolic pressure and diastolic pressure of the central obesity group were 8.24 mm Hg [95%CI (1.03, 15.46) mm Hg,P=0.026] and 6.79 mm Hg [95%CI (2.03, 11.55) mm Hg, P=0.006] higher than those in the normal WC group, respectively. For the normal WC or normal BMI subjects, the detection rate of dyslipidemia reached up to 50.0% and 52.6%. Conclusions With the increase of BMI/WC values, the level of blood pressure rises. Even though WC or BMI is normal, the detection rate of dyslipidemia is high.
Objective To summarize the advance of bioenergetic metabolic mechanisms of cancer cell. Methods Literatures about the recent studies on the bioenergetic metabolic mechanisms of cancer cell were reviewed.Results Cancer cells required a steady source of metabolic energy in order to continue their uncontrolled growth and proliferation. Accelerated uptake of glucose and glycolysis was one of the biochemical characteristics of hypoxia cancer cells. Glucose transport and metabolism were essential for the survival of tumor cells, leading to poor prognosis. Conclusions The studies on relationships between hypoxia-inducible genes and cancer have come a new understanding of the bioenergetic metabolic mechanisms of cancer cell, become new and important supplementary means of diagnosis and treatment of cancer, and enhanced existing strategies so that the treatment could be more rationally applied and personalized for cancer patients.
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 explore the expressions of glucose regulated protein (GRP) 78 and GRP94 in rectal adenocarcinoma and their clinical significances. MethodsIn 45 paraffin-embedded sections of rectal adenocarcinoma tissues and adjacent normal tissues, the expressions of GRP78 and GRP94 were examined by EnVisionTM. ResultsThe positive rates of GRP78 and GRP94 protein expression in the rectal adenocarcinoma tissues were 53.33% (24/45) and 53.33% (24/45), while those in the adjacent normal tissues were 13.33% (6/45) and 15.56% (7/45), respectively. There was a statistical significance of the expression of GRP78 or GRP94 between the tumor tissues and the adjacent normal tissues (all P < 0.001), and it was found that the positive expression rates were relevant to the extent of differentiation, Dukes stage, and lymph node metastasis of cancer (all P < 0.05), but not to the patient's sex, age, and size of tumor (all P > 0.05). And there was a statistical significance in Spearman method about the rate of positive expression between GRP78 and GRP94 (rs=0.464, P < 0.01). ConclusionGRP78 and GRP94 protein is highly expressed in rectal adenocarcinoma tissue, related to its metastasis and invasion, might be used as a useful indicator to judge the malignant degree.
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.