THE EFFECT OF Y-25510 INJECTION ON THE SERUM LEVELS OF SOME CYTOKINESIN HEALTHY ADULT VOLUNTEERS

Objective: Y-25510 was administered by means of an intravenous drip in fusion to healthy adult male volunteers at a dose of 40, 80 or 160 mg in a single-dose study, and at a dose of 160 mg once a day for 7 days in a multiple-dose study. Results: Serum levels of interleukin (IL)-1 beta, IL-6 and IL-10 were significantly increased, but there was no ch ange in leukocyte and platelet counts. The peak serum concentration of IL-1 beta was nearly maximum at the single doses of 40 and 80 mg, and at the multiple dose of 160 mg per day. The peak serum concentration of IL-6 increased in a dose-dependent manner at a dose of 40 mg or mor e. For the multiple-dose study, the serum level of IL-10, which remain ed unchanged in the placebo group, began to increase in the Y-25510 gr oup following the maximum serum level of IL-1 beta and IL-6. There wer e no clinically relevant differences in body temperature and blood pre ssure after the administration of Y-25510. Conclusion: These findings that leukocyte and platelet counts never increased, despite the increm ent of the IL-1 beta and IL-6 production after the administration of Y -25510, may be explained in part by the negative feedback mechanism in duced by IL-10.