CISPLATIN INDUCES SEROTONIN RELEASE FROM HUMAN PERIPHERAL-BLOOD MONONUCLEAR-CELLS OF CANCER-PATIENTS AND METHYLPREDNISOLONE INHIBITS THIS EFFECT

The aim of this study was to verify whether cisplatin (CDDP) can induc e serotonin (5HT) release from peripheral blood mononuclear cells (PBM C) of cancer patients and determine whether methylprednisolone (MP) ca n inhibit such release. Ten patients (mean age 61.8 years) with cancer of different sites, all but one in advanced stage of disease were stu died. Our study showed that unstimulated PBMC of cancer patients relea se a higher amount of 5HT than that of healthy subjects (57+/-5 nM vs 10+/-1 nM, p<0.001) and that similarly the stimulation with PHA or CDD P induces a higher amount of 5HT release by PBMC of cancer patients th an that by PBMC of healthy subjects (74+/-6 vs 32+/-3 nM, p<0.001 and 91+/-8 vs 18+/-2 nM, p<0.001, respectively). The addition of MP to the culture in the presence of CDDP induced a significant decrease of 5HT levels: from 91+/-8 to 53+/-7 nM, p=0.002. This result obtained in ca ncer patients paralleled that previously obtained by us in healthy sub jects. Our data confirm a new mechanism through which CDDP could induc e emesis and provide a further possible explanation to the anti-emetic activity of corticosteroids, such as MP.