Serotonin production in lymphocytes and mercury intolerance

Patients with suspected illness due to mercury in dental amalgam were class ified as tolerant or intolerant depending on their psychosomatic responses following in vivo epicutaneous provocation with low doses (patch test doses ) of metallic mercury and phenylmercuric acetate. Ten intolerant patients a nd nine tolerant patients plus seven healthy amalgam-free and metal non-all ergic controls were recruited to the study. Peripheral blood lymphocytes we re exposed in vitro to three concentration of mercuric chloride (0.92, 1.83 and 3.68 mu M) with and without 10 mu g phytohaemagglutinine (PHA)/ml and the release of serotonin into the supernatant was measured. Lymphocytes exp osed only to HgCl2 showed no significant dose-dependent increase of seroton in, but the response of the tolerant patients was significantly higher comp ared with the controls. No other differences were found. Co-culture with me rcuric chloride and PHA showed a statistically significant dose-dependant r elease of serotonin, but no differences between the three clinical groups c ould be detected. Thus, our results could not validate the concept of mercu ry tolerance and intolerance. (C) 2000 Elsevier Science Ltd. All rights res erved.