Temporal sequence of chemiluminescence and aggregation of human neutrophils and platelets after stimulation by arachidonic acid

Abstract

Using the instrument known as a lumiaggregometer we have simultaneously measured chemiluminescence (CL) and aggregation (Ag) of neutrophils and platelets. The CL and Ag responses are triggered by the addition of 10 −4 M arachidonate. We note that chemiluminescence occurs before aggregation of neutrophils (10 sec) and platelets (16 sec). Arachidonate is known to hasten 45Ca transport in cellular membranes which probably triggers cellular metabolism to cause chemiluminescence. Additionally metabolized arachidonate or fatty acids are known to cause CL by cyclooxygenase-peroxidase and lipoxygenase pathways via free radicals. Since free radicals are known to react with luminol the CL is enhanced. These free radicals metabolites must occur before the physical event of aggregation.