Influence of several plasma fractions on post-ischemic microvascular reperfusion in the central nervous system.

Abstract

The hypothesis that plasma contains native constituents capable of interacting in zones of acute tissue damage to impair microcirculatory flow was tested. 14C-antipyrine autoradiographic blood flow studies were performed in 30 splenectomized dogs subjected to 35 min of cerebrospinal fluid compression ischemia followed by 30 min of recirculation to the neuraxis. The animals were all anticoagulated with heparin and were divided into 7 groups by exposure to various measures prior to induction of ischemia. Groups 1 and 2 served for comparison with the other groups and underwent, respectively, no glass-wool filtration and glass-wool filtration via an arteriovenous shunt. Post-ischemic brain blood flows in Group 1 were low and focal zones of greatly impaired reperfusion were present. In Group 2, post-ischemic brain blood flows were high and focal perfusion impairment did not occur. Groups 3-7 received 1 of several plasma fractions after glass-wool filtration in order to identify those with activity that nullified the enhancement of post-ischemic reperfusion expected after exposure to glass-wool. The infused plasma fractions included: homologous cryoprecipitate in Group 3, autologous cryoprecipitate in Group 4, autologous cryoprecipitate-poor plasma in Group 5, plasma concentrate containing molecules over 10,000 daltons in Group 6 and plasma ultra filtrate containing molecules of less than 10,000 daltons in Group 7. Brain blood flows in Group 3, 4 and 6 resembled those in Group 1 while the flows in Groups 5 and 7 were like those in Group 2. Activity deleterious to post-ischemic reperfusion apparently resides in the cryoprecipitate fraction of plasma and is associated with molecules exceeding 10,000 daltons.