Thrombin inhibitor reduces leukocyte-endothelial cell interactions and vascular leakage after scatter laser photocoagulation.
OBJECTIVE
Macular edema is one of the most serious adverse effects after retinal scatter laser photocoagulation. It has been suggested that the inflammatory reaction after photocoagulation may be involved in the pathogenesis of macular edema. This study was designed to evaluate quantitatively the inhibitory effects of argatroban, a direct thrombin inhibitor, on leukocyte-endothelial cell interactions and vascular permeability after scatter laser photocoagulation.


METHODS
Argon laser photocoagulation was performed in one half of the retina in pigmented male rats (n = 114). Argatroban was administered just before scatter laser photocoagulation. In the other half of the retina, AO leukocyte fluorography was used to evaluate in vivo leukocyte rolling along the retinal vein and accumulation in the retinal capillary bed. The expressions of P-selectin and intercellular adhesion molecule (ICAM)-1 were evaluated by reverse transcription-polymerase chain reaction. Retinal vessel permeability was quantified by using fluorescein isothiocyanate (FITC)-conjugated dextran.


RESULTS
Scatter laser photocoagulation caused significant inflammatory leukocyte-endothelial cell interactions in the nonphotocoagulated half of the retina. Treatment with argatroban suppressed leukocyte-endothelial cell interactions. The maximum number of rolling and accumulating leukocytes was reduced by 46.6% (P < 0.01) and 51.4% (P < 0.01), respectively. The expression of P-selectin and ICAM-1 mRNA was suppressed significantly in the argatroban-treated retinas (P < 0.05). Retinal vascular permeability was also suppressed significantly (P < 0.05).


CONCLUSIONS
Argatroban suppressed leukocyte-endothelial cell interactions and blood-retinal barrier breakdown after scatter laser photocoagulation, suggesting that argatroban prevents postlaser macular edema.
Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan.
Kunihiro
K
Musashi
Junichi
J
Kiryu
Kazuaki
K
Miyamoto
Shinsuke
S
Miyahara
Hideto
H
Katsuta
Hiroshi
H
Tamura
Fumitaka
F
Hirose
Nagahisa
N
Yoshimura
D000818:Animals; D000925:Anticoagulants / Q000494:pharmacology*; D001120:Arginine / Q000031:analogs & derivatives; D001813:Blood-Retinal Barrier / Q000187:drug effects*; D002199:Capillary Permeability / Q000187:drug effects; D002448:Cell Adhesion / Q000187:drug effects; D003911:Dextrans; D004730:Endothelium, Vascular / Q000502:physiology*; D016650:Fluorescein-5-isothiocyanate / Q000031:analogs & derivatives*; D018799:Intercellular Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism; D017075:Laser Coagulation / Q000009:adverse effects*; D007962:Leukocytes / Q000502:physiology*; D008269:Macular Edema / Q000209:etiology / Q000517:prevention & control*; D008297:Male; D019007:P-Selectin / Q000235:genetics / Q000378:metabolism; D010875:Pipecolic Acids / Q000494:pharmacology*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D020318:Rats, Long-Evans; D012160:Retina / Q000601:surgery; D012171:Retinal Vessels / Q000187:drug effects; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013449:Sulfonamides; D013917:Thrombin / Q000037:antagonists & inhibitors*
D000925:Anticoagulants; D003911:Dextrans; D019007:P-Selectin; D010875:Pipecolic Acids; D012333:RNA, Messenger; D013449:Sulfonamides; C015219:fluorescein isothiocyanate dextran; D018799:Intercellular Adhesion Molecule-1; D001120:Arginine; D013917:Thrombin; D016650:Fluorescein-5-isothiocyanate; C031942:argatroban