Platelet serotonergic mechanisms in patients with cancer of the urinary bladder

Platelet reactivity of hypertensive patients and patients with cancer of th e urinary bladder was examined in vitro in comparison with normotensive pat ients. A significant increase in free serotonin in the plasma of patients w ith cancer of the bladder and a less pronounced increase in hypertensive su bjects was observed. The platelets in neoplastic disease and hypertension s howed a significant reduction in the kinetics of serotonin uptake. However, the release reaction was markedly higher, compared with healthy volunteers . Enhancement of platelet aggregation with serotonin was much greater in pa tients with cancer of the bladder than in control groups and in hypertensiv e patients. These data indicate increased sensitivity to serotonin within t he platelets of patients with cancer of the urinary bladder. (C) 2000 Elsev ier Science Ltd. All rights reserved.