Hemodynamic depression and microthrombosis in the peripheral areas of cortical contusion in the rat: role of platelet activating factor.
Cerebrovascular damages leading to subsequent reductions in regional cerebral blood flow (rCBF) may play an important role in secondary cell damages following traumatic brain injury (TBI). Recent studies have demonstrated that rCBF markedly decrease in experimental model of TBI (e.g. fluid percussion injury, acute subdural hematoma, contusion). However, precise mechanisms underlying post-traumatic CBF reduction remain unclear. In the present study, the rCBF changes and microthrombosis formation were investigated in a cortical contusional model in rats, and the effects of etizolam (platelet activating factor antagonist) on microthrombosis were tested. The rCBF in the peripheral areas increased transiently, and decreased to ischemic level 3 hours post- injury. The histological examinations revealed microthrombosis formation in the contused area, extending from the center to the peripheral areas within 6 hours post-injury. The rCBF decrease and the contusion necrosis volume were significantly attenuated by etizolam administration. These results indicate that platelet activating factor is involved in microthrombosis formation and hemodynamic depression, and resultant ischemic damages within areas surrounding the contusion.
Maeda
T
T
Department of Neurological Surgery, Nihon University School of Medicine, Tokyo, Japan.
Katayama
Y
Y
Kawamata
T
T
Aoyama
N
N
Mori
T
T
D000818:Animals; D001924:Brain Concussion / Q000503:physiopathology*; D002540:Cerebral Cortex / Q000293:injuries*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D003975:Diazepam / Q000031:analogs & derivatives / Q000494:pharmacology; D006439:Hemodynamics / Q000502:physiology*; D008297:Male; D010972:Platelet Activating Factor / Q000037:antagonists & inhibitors / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D013927:Thrombosis / Q000503:physiopathology*
D010972:Platelet Activating Factor; C044610:etizolam; D003975:Diazepam