Ozagrel reverses streptozotocin-induced constriction of arterioles in rat retina.
Retinal blood flow decreases early in the progression of diabetic retinopathy; however, the mediators and mechanisms responsible for this decrease have yet to be determined. In this study, diabetes was induced by streptozotocin in rats, and retinal blood flow was measured via intravital microscopy 1 or 3 weeks following the induction of hyperglycemia. Additionally, retinal arteriolar diameters and flow were measured prior to and following acute administration of the thromboxane synthase inhibitor ozagrel to investigate the potential role of thromboxane in the observed constriction. Minimal changes in the retinal diameters and flow were observed at 1 week of diabetes; however, at 3 weeks of diabetes, arteriolar constriction and decreases in blood flow were significant. Notably, the constriction occurred only in the arterioles that were in closer proximity to the venules draining the retina. Acute administration of ozagrel reversed the constriction of the closely venule-paired arterioles. In summary, the results suggest that thromboxane mediates localized, venule-dependent arteriolar constriction induced by streptozotocin-induced diabetes in rats.
Lee
Seungjun
S
Louisiana State University Health Sciences Center, Department of Molecular and Cellular Physiology, 1501 Kings Highway, Shreveport, LA 71115, USA.
Morgan
Georgia A
GA
Harris
Norman R
NR
D000818:Animals; D001160:Arterioles / Q000187:drug effects / Q000503:physiopathology; D003921:Diabetes Mellitus, Experimental / Q000503:physiopathology; D003930:Diabetic Retinopathy / Q000503:physiopathology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D008297:Male; D008689:Methacrylates / Q000494:pharmacology*; D008856:Microscopy, Fluorescence; D051381:Rats; D017208:Rats, Wistar; D012171:Retinal Vessels / Q000187:drug effects* / Q000503:physiopathology; D013311:Streptozocin / Q000037:antagonists & inhibitors* / Q000633:toxicity; D013930:Thromboxane-A Synthase / Q000037:antagonists & inhibitors; D014661:Vasoconstriction / Q000187:drug effects
D004791:Enzyme Inhibitors; D008689:Methacrylates; D013311:Streptozocin; D013930:Thromboxane-A Synthase; C034364:ozagrel