[Melatonin production in thrombocytes and their functional activity in patients with aspirin asthma]

The aim of the investigation was to study melatonin production in thrombocytes and their functional activity in correlation with 6-sulfatoximelatonin (6-SOM) urinary excretion in patients with aspirin-induced bronchial asthma (AIBA). Forty-three patients with bronchial asthma (BA) were examined. The main group consisted of 26 AIBA patients; the comparison group consisted of 17 BA patients with no intolerance to aspirin or other non-steroidal anti-inflammatory drugs; 30 practically healthy individuals constituted the control group. The study found no melatonin production in thrombocytes of AIBA patients: only 13.0 +/- 1.3% of platelets expressed melatonin, while in healthy people 97.7 +/- 0.6% of the cells did. Besides, daytime urinary excretion of 6-SOM, the main melatonin metabolite, was lower in AIBA patients. Lower daytime and higher nighttime melatonin production in AIBA patients correlated with the acceleration of the 1st phase and increased intensity of thrombocyte aggregation, which evidences high thrombocyte reactivity to the inducing agent. The presence of a pathologic reaction of thrombocytes to exogenous melatonin, manifesting by changes in the 1st stage of aggregation, suggests the presence of pathology in thrombocyte membrane-receptor complex and the calcium homeostasis of the cell, which determines constant activation and the participation of thrombocytes in the development of asthmatic syndrome.