OxyFile #131

Biochimica et Biophysica Acta, 718 (1982) 21-25
Elsevier Biomedical Press

Hydrogen Peroxide Release from Human Blood Platelets

A. Finazzi-Agro, A. Menichelli, M. Persiani, G. Biancini, & D. Del 
Principe

The release of hydrogen peroxide from human blood platelets after 
stimulation with particulate membrane-perturbing agents has been 
determined by fluorescence using scopoletin as the detecting agent.  
Platelet suspensions containing less that 1 polymorphonuclear 
leukocyte /10(8) platelets showed a significant release of hydrogen 
peroxide (6.11 nmol/10(9) platelets per 20 min, S.D., 0.26, n=9) 
after addition of zymosan or latex particles, compared to 
unstimulated platelets.  The release of hydrogen peroxide was only 
observed when the scopoletin was added to the platelet suspensions 
during the stimulation.  Any attempt to determine hydrogen peroxide 
release in the supernatant at the end of the incubation with zymosan 
or latex failed.  A NADH-dependent production of hydrogen peroxide 
was observed by measuring the difference of oxygen uptake in the 
presence and absence of catalase (500 units), which was not inhibited 
by potassium cyanide (1 mM).  By this method the NADH-dependent 
cyanide-insensitive peroxide production and release was 6.0 
nmol/10(9) platelets per 20 min from resting platelets (S.D., 2, n=6) 
vs. 15 nmol/10(9) platelets per 20 min from stimulated platelets 
(S.D., 2, n=6).


Key words:  Hydrogen peroxide release; NADH oxidase; (Human platelet)