Platelet accumulation in regions of low blood flow during the postischemic period.

Abstract

After a latent interval, a progressive focal deterioration of microvascular perfusoin can develop in zones of acute damage to the central nervous system (CNS). To obtain reliable information concerning the possibility of platelet participation in this phenomenon, platelet deposition was investigated by means of 111In-labeled platelets, and compared with local cerebral blood flow (CBF) and cortical sensory evoked response (CSER). Studies were performed with a model of focal ischemia in which small volumes of air were injected selectively into 1 internal carotid artery of dogs anesthetized with .alpha. chloralose throughout the experiment. The ischemic period was followed by a 10-min, 60-min or 4-h recovery period. A prominent and diffuse accumulation of platelets resulted in zones of low CBF in dogs subjected to 4 h recovery.