Objective To observe the effects of simvastatin on endothelial progenitor cells (EPCs) from peripheral blood and retinopathy in rats with diabetic retinopathy (DR). Methods Eighty male Wistar rats were divided into normal control group (group A), DR model group (group B), DR with placebo group (group C), DR with simvastatin group (group D), with twenty rats in each group. The rats in group C and D received streptozotocin (STZ) injection to induce diabetic retinopathy. The rats in the group A and B were not intervened. The rats were gavaged with 20 mg/kg simvastatin (group D) or same volume of distilled water (group C) once a day. Flow cytometry was used to identify and count the number of EPCs from peripheral blood at the 1st，4th and 12th week after injection. Evans blue perfusion was used to detect the bloodretinal barrier (BRB) permeability. Immunohistochemical staining was used to observe the expression of CD31 in the retina. Real-time reverse transcriptionpolymerase chain reaction (RT-PCR) was used to measure the mRNA expression of eNOS, iNOS and Ang-1. The correlation between changes of EPCs and DR morphological changes was analyzed. Results At the 1st，4th and 12th week after injection, compared with the group A, the number of EPCs was decreased in group C; Compared with the group B and C, the number of EPCs was increased in group D (t=4.967, 5.648, 6.688, 6.042, 7.392, 7.454;P＜0.05); there was no statistical difference of EPCs number between group B and C (t=0.525, -0.249, -0.619; P＞0.05), group A and D (t=6.733, 2.794, -5.535; P＜0.05) respectively. The structure of retina was continuous and its capillary structure was normal in control group. The retinal layers were edema and the retina developed telangiectatic vessels and many ganglion cells developed vacuolar degeneration in group B and C. The layers tissue of retina was less edema and gradually arranged in group D. The BRB permeability was significantly increased in group B and D compared with group A. The BRB permeability was significantly decreased in group D compared with group B (F=65.808，P＜0.05). The CD31 expression in group D was obviously higher than that in group A, B and C (F=24.799，P＜0.05). The eNOS expression in group B was obviously lower than that in group A, while in group D was obviously higher than that in group B (t=-2.750，2.230；P＜0.05). The iNOS and Ang-1 expression in group B were obviously higher than those in group A, while in group D was obviously lower than that in group B (t=3.881，-1.144，4.244，-1.458；P＜0.05). There was no difference in BRB permeability, eNOS, iNOS and Ang-1 expression between group B and C (t=0.480,-0.877, 0.062, 0.220; P＞0.05). Conclusions Simvastatin could mobilize DR rats peripheral blood EPCs, induce migration and differentiation of retinal endothelial cell, slow down the DR progress by regulating the expression of endothelium factors such as eNOS and iNOS.
Objective To investigate the amounts of endothelial progenitor cells (EPCs) in peripheral blood of patients with proliferative diabetic retinopathy (PDR). Methods Forty patients with PDR (PDR group), thirty patients with type 2 diabetes mellitus (DM) without DR (DM group), and twenty age-matched normal subjects (control group) were enrolled in this study. Blood samples were treated by repeated centrifugation and stained with monoclonal antibodies. At least 2times;105 cells were analyzed by flow cytometry. EPCs were identified by CD34 and CD133 antibody. The correlation between EPCs numbers and DR duration, glycosylated hemoglobin, serum lipids was analyzed. Results The number of EPCs in PDR, DM and control group were (49plusmn;12)、(35plusmn;11)、(90plusmn;25) cells/ml respectively, the difference was statistically significant (F=56.260, P=0.000). There was a positive correlation between EPCs numbers and DR duration (r=0.564, P＜0.05). However there was no correlation between EPCs numbers and glycosylated hemoglobin (r=-0.170, P＞0.05) or triglyceride levels (r=0.261, Pgt;0.05). Conclusions The number of EPCs in peripheral blood of PDR patients was decreased. EPCs might play an important role in the pathogenesis of PDR.
Objective To evaluate the change of blood sugar in diabetic patients after vitrectomy and analyze the relative reasons. Methods Nineteen diabetes II patients (20 eyes) who underwent vitrectomies received the tests of blood sugar preoperatively, and 1～2 hours, 1, 3, and 5 days postoperatively. Analysis of variance, apaired Studentrsquo;s t-test, and correlation analysis were used to analyze the change of postoperative blood sugar and correlation between postoperative blood sugar change and its relative factors. Results Postoperative blood sugar increased significantly compared with the preoperative one (Plt;0.05),reached the peak 1～2 hours postoperatively, and reached almost the preoperative level 5 days postoperatively (Pgt;0.05). There was a positive correlation between blood sugar increase and operation time, preoperative blood sugar level, and diabetic duration (Plt;0.05). Postoperative blood sugar was relative to potentiated anesthesia. Conclusion There is a regularity that blood sugar increases just postoperatively and reaches the preoperative level 5 days postoperatively. The relative factors to blood sugar change include preoperative blood sugar level, diabetic duration, operation time, and potentiated anesthesia. (Chin J Ocul Fundus Dis,2000,16:157-159)