Argatroban attenuates leukocyte- and platelet-endothelial cell interactions after transient retinal ischemia.
OBJECTIVE
Argatroban, a direct thrombin inhibitor, has been shown to reduce neural injury after transient cerebral ischemia. It has also been reported that this neuroprotective effect results from an anticoagulant function. This study was designed to evaluate quantitatively the inhibitory effects of argatroban on leukocyte- and platelet-endothelial cell interactions after transient retinal ischemia.


METHODS
Retinal ischemia was induced for 60 minutes in male Long-Evans rats by temporary ligation of the optic sheath (n=342). Argatroban was administered just after induction of ischemia. Leukocyte and platelet behavior in the retinal microcirculation was then evaluated in vivo with scanning laser ophthalmoscopy. The expression of P-selectin and intracellular adhesion molecule-1 (ICAM-1) was evaluated by reverse transcription-polymerase chain reaction. After 10 days of reperfusion, ischemia-induced retinal damage was evaluated histologically.


RESULTS
Treatment with argatroban suppressed leukocyte-endothelial cell interactions; the maximum numbers of rolling and accumulated leukocytes were reduced by 90.1% (P<0.05) and 58.7% (P<0.05), respectively, at 12 hours after reperfusion. Treatment with argatroban also suppressed platelet-endothelial cell interactions; the maximum numbers of rolling and adhering platelets were reduced by 91.8% (P<0.01) and 78.9% (P<0.01), respectively, at 12 hours after reperfusion. The expression of P-selectin and ICAM-1 mRNA was suppressed significantly in the argatroban-treated retinas (P<0.01). Histologic examination demonstrated the protective effect of argatroban on ischemia-induced retinal damage (P<0.01).


CONCLUSIONS
Argatroban treatment suppressed leukocyte- and platelet-endothelial cell interactions after transient retinal ischemia. This inhibitory effect on postischemic blood cell-endothelial cell interactions might partially contribute to its neuroprotective effects.
Miyahara
Shinsuke
S
Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawaramachi Sakyo-ku, Kyoto-shi, Kyoto, 606-8507, Japan.
Kiryu
Junichi
J
Tsujikawa
Akitaka
A
Katsuta
Hideto
H
Nishijima
Kazuaki
K
Miyamoto
Kazuaki
K
Yamashiro
Kenji
K
Nonaka
Atsushi
A
Honda
Yoshihito
Y
D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives; D001792:Blood Platelets / Q000187:drug effects* / Q000502:physiology; D002448:Cell Adhesion / Q000187:drug effects; D004195:Disease Models, Animal; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000503:physiopathology; D015870:Gene Expression / Q000187:drug effects; D018799:Intercellular Adhesion Molecule-1 / Q000235:genetics; D007511:Ischemia / Q000188:drug therapy*; D007962:Leukocytes / Q000187:drug effects* / Q000502:physiology; D008297:Male; D019007:P-Selectin / Q000235:genetics; D010314:Partial Thromboplastin Time; D010875:Pipecolic Acids / Q000494:pharmacology*; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology; D011517:Prothrombin Time; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D020318:Rats, Long-Evans; D015424:Reperfusion; D012160:Retina / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D012164:Retinal Diseases / Q000188:drug therapy* / Q000503:physiopathology; D012171:Retinal Vessels / Q000187:drug effects / Q000503:physiopathology; D013449:Sulfonamides; D013917:Thrombin / Q000037:antagonists & inhibitors; D016896:Treatment Outcome; D014654:Vascular Patency / Q000187:drug effects
D019007:P-Selectin; D010875:Pipecolic Acids; D010975:Platelet Aggregation Inhibitors; D012333:RNA, Messenger; D013449:Sulfonamides; D018799:Intercellular Adhesion Molecule-1; D001120:Arginine; D013917:Thrombin; C031942:argatroban