Objective To observe the effect of celecoxib on the expression vascular endothelial growth factors (VEGF) in diabetic rats. Methods Thirty-six wistar rats were used to establish the diabetic models by intraperitoneal injection with streptozotocin. The diabetic rats were divided into 2 groups: diabetic group (n=18) and celecoxib group (n=18). Celecoxib (50 mg/kg) was administered orally to the rats in celecoxib group and the physiological saline with the same volume was given orally to the rats in diabetic group. Eighteen else rats were in normal control group. All of the rats were executed 3 months later. The expression of VEGF protein was detected by immunohistochemistry method. Reverse transcription-polymerase chain reaction（RT-PCR） analysis was used to examine the expression of retinal VEGF mRNA and cyclooxygenase-2 mRNA. Results Lower positive expression of VEGF mRNA and cyclooxygenase-2 mRNA, weakly positive action of immunohistochemistry of VEGF, and lower expression of VEGF protein were detected in normal control group; in the diabetic group, the expression of VEGF mRNA and cyclooxygenase-2 mRNA increased obviously comparing with which in the control group (Plt;0.05), and the bly positive action of immunohistochemistry of VEGF and increased expression of VEGF protein were detected (Plt;0.01); in celecoxib group, the expression of VEGF mRNA was lower than that in the diabetic group (Plt;0.05), the expression of cyclooxygenase-2 mRNA didnprime;t decrease much (Pgt;0.05), the positive action of immunohistochemistry of VEGF decreased, and the expression of VEGF protein decreased (Plt;0.01). Conclusion By inhibiting the activation of cyclooxygenase-2, celecoxib can inhibit the expression of retinal VEGF mRNA and protein in diabetic rats induced by streptozotocin. (Chin J Ocul Fundus Dis,2007,23:265-268)
Objective To investigate the effect of intravitreal injection with dexamethasone on leukocyte accumulation, vascular permeability, and the expression of intercellular adhension molecule (ICAM-1) in rats with diabetes. Methods Seventy-two BN rats were divided into 4 groups: control group, diabetes group, diabetes+ physiologic saline group, and diabetes+ dexamethasone group, with 18 rats in each group. Streptozotocin was injected into the rats to set up the diabetic model. Accumulated leukocytes were counted in vivo by acridine orange leukocyte fluorography, and retinal vascular permeability was measured by Evans blue assay. The expression of mRNA and protein level of ICAM-1 were evaluated by real-time quantitative polymerase chain reaction analysis and enzymelinked immunosorbent assay. Results In the diabetes+ dexamethasone group, accumulated leukocytes were reduced, retinal vascular permeability decreased, and the expression of ICAM-1 decreased. The expression of ICAM-1 mRNA and protein levels in control group, diabetes group, diabetes+ physiologic saline group, and diabetes+ dexamethasone group were 0.43plusmn;0.07，0.76plusmn;0.21，0.74plusmn;0.18，and 0.55plusmn;0.13; (37.90plusmn;4.56), (76.74plusmn;6.68), (74.32plusmn;7.11), and (39.61plusmn;4.47) pg/mg respectively. Conclusions Dexamethasone can reduce accumulated leukocytes and retinal vascular permeability, which may be caused by inhibiting the expression of ICAM-1. (Chin J Ocul Fundus Dis,2007,23:273-276)