[Serotonin: a novel marker for atherosclerotic vascular disease].

Serotonin is released from nerve terminals distributed at the intestinal chromaffin cells, which are taken up into platelets. The serotonin is released at the site where platelets are activated in such situations as atherosclerotic vascular lesions. Therefore, we assumed that the serotonin level could be a suitable marker for atherosclerosis. We developed a new high-performance liquid chromatographic (HPLC) method, including a column-switching system and a post-column reaction with benzylamine, for measurement of serotonin levels in samples from patients with coronary heart disease. The vacuum tubes containing the 3mg/ml (7.4mmol/l) of ethylenediaminetetraacetic acid dipotassium (EDTA2K) were used for collecting the samples of platelet-poor plasma (PPP) because the concentration of anticoagulant in the commercially available vacuum tube containing the 1-2mg/ml (2.5-5.0mmol/l) of EDTA2K was not enough. The serotonin levels in PPP and whole blood of healthy subjects and 4 groups of patients with effort angina pectoris (e-AP), unstable angina (u-AP), old myocardial infarction (OMI), and vasospstic angina pectoris (VSAP), were determined by using the developed method. The serotonin levels in PPP from patients of u-AP, OMI, and VSAP were significantly higher than those of healthy subjects(p<0.001, p<0.005, and p<0.001). The ratio of PPP to whole blood of all disease groups were significantly higher than those of healthy subjects (p<0.001). From these findings, we propose that serotonin is useful as a novel marker for atherosclerotic vascular disease.