Zymosan-induced chemiluminescence of granulocytes in incubated human whole blood. The role of platelets.

Zymosan-induced chemiluminescence (ZI-CL) of whole blood which is mainly the response of granulocytes can be used as a rapid, simple and reliable diagnostic tool for hematological and allergic disorders. ZI-CL of whole blood remained unchanged when stored at 0 degree C for 4 hr, whereas it increased by incubation at 37 degrees C. This phenomenon points to platelet-granulocyte interaction during the incubation. ZI-CL of freshly prepared suspension of leukocytes and erythrocytes was enhanced by adding platelet rich plasma (PRP) obtained from incubated blood. Enhanced CL response was observed when erythrocytes or factors derived there of were present in incubated blood. Platelet stimulating factor (PSF) was prepared from incubated erythrocyte suspension. This factor also increased ZI-CL of granulocytes when incubated with fresh PRP. The consistent inhibition of CL of incubated blood by apyrase (0.5 U/ml) and the increased response of fresh blood by the addition of ADP (10(-5) M) suggested that this factor might be ADP itself. Platelets stimulated by this factor may respond more markedly to added zymosan for still unexplored reason with enhanced CL.