Dexamethasone inhibits leukocyte accumulation and vascular permeability in retina of streptozotocin-induced diabetic rats via reducing vascular endothelial growth factor and intercellular adhesion molecule-1 expression.
Intravitreal injection of corticosteroid has been used to treat diabetic macular edema, however, the exact mechanism remains unknown. In the present experiment, four weeks after streptozotocin administration, intravitreal injection of dexamethasone (50 microg/10 microl) was performed. After 2 d injection, we investigated the effect of dexamethasone on leukocyte accumulation, vascular permeability and the expression of vascular endothelial growth factor (VEGF) and intercellular adhesion molecule-1 (ICAM-1) in streptozotocin-diabetic rats. Accumulated leukocytes were counted in vivo by acridine orange leukocyte fluorography, the retinal vascular permeability was measured by the Evans blue assay. The mRNA and protein level of VEGF and ICAM-1 were analyzed with real-time quantitative polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA) respectively. Dexamethasone downregulated VEGF and ICAM-1 expression in diabetic rats which correlated with its effect on leukocytes accumulation and retinal vascular permeability. The present data revealed that dexamethasone may inhibit retinal accumulation and leukostasis accumulation and vascular permeability through its blockage on VEGF and ICAM-1 expression.
Wang
Kang
K
Department of Ophthalmology, Beijing Capital Medical University Affiliated Beijing Friendship Hospital, Beijing, China.
Wang
Yanling
Y
Gao
Lixin
L
Li
Xinmin
X
Li
Mingming
M
Guo
Jianyou
J
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000494:pharmacology*; D001786:Blood Glucose / Q000378:metabolism; D001813:Blood-Retinal Barrier / Q000187:drug effects*; D002199:Capillary Permeability / Q000187:drug effects; D003907:Dexamethasone / Q000008:administration & dosage / Q000494:pharmacology*; D003921:Diabetes Mellitus, Experimental / Q000473:pathology*; D015536:Down-Regulation / Q000187:drug effects; D004797:Enzyme-Linked Immunosorbent Assay; D007267:Injections; D018799:Intercellular Adhesion Molecule-1 / Q000096:biosynthesis* / Q000502:physiology; D007962:Leukocytes / Q000187:drug effects*; D008297:Male; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D051381:Rats; D011914:Rats, Inbred BN; D020133:Reverse Transcriptase Polymerase Chain Reaction; D042461:Vascular Endothelial Growth Factor A / Q000096:biosynthesis* / Q000502:physiology; D014822:Vitreous Body
D000893:Anti-Inflammatory Agents; D001786:Blood Glucose; D012333:RNA, Messenger; D042461:Vascular Endothelial Growth Factor A; D018799:Intercellular Adhesion Molecule-1; D003907:Dexamethasone