Augmentative effect of OK-432 and/or Nocardia rubra cell wall skeleton on superoxide generation from polymorphonuclear leukocytes

Abstract

Effects of OK-432 and/or Nocardia rubra cell wall skeleton (NCWS) on superoxide generation from polymorphonuclear leukocytes (PMN) were studied by the new method of Cypridana luciferin analog-dependent chemiluminescence. Superoxide generation from the rat peritoneal PMN stimulated by phorbol myristate acetate or opsonized zymosan was augmented by the 8-day subcutaneous injection of OK-432 or NCWS in vivo, but neither by the 3-day subcutaneous injection nor by the incubation of PMN with OK-432 or NCWS in vitro. Combined 8-day subcutaneous treatment with OK-432 and NCWS induced marked increase in the superoxide generation from PMN stimulated by opsonized zymosan. OK-432 or NCWS did not directly stimulate PMN to generate superoxide under the condition we tested. It is suggested that the increased generation of oxygen radicals induced by OK-432 and/or NCWS may play a beneficial role in the tumoricidal activity exhibited by PMN, and that the augmentative offect of OK-432 and/or NCWS may not be direct.