Cathechol-O-methyl transferase activity in the individual human platelet populations.

COMT activity is present in many animal tissues, but there is no evidence on the presence or the functional role of COMT activity in platelets. The present work reports the results obtained on COMT activity in the individual platelet populations separated by a discontinuous sucrose density gradient. In the young platelet populations the activity is remarkable higher than in the old and light populations. Low values of COMT activity in the old platelets may reflect platelet senescence.