Abstract

We studied the effects of OKY-046 on types II, III and IV allergic reactions, as classified by Coombs and Gell. In Type II, OKY-046 at 30-100 mg/kg intraduodenally (i.d.) and at 1-30 mg/kg intravenously (i.v.) inhibited the bronchoconstriction in a dose-dependent manner after Forssman antigen injection. Aspirin (3 mg/kg, i.v.) also suppressed it. OKY-046 (30-100 mg/kg, i.d.) suppressed the increase of TXB₂ level in the plasma in a dosedependent manner. However, there was no effect of OKY-046 and aspirin on the decrease in complement activity (CH₅₀), platelets and leukocytes. Additionally, OKY-046 (300 mg/ kg, p.o.) prolonged the survival time following Forssman antigen injection. However, the immune hemolysis reaction was not prevented by OKY-046 (10^-6-10^-3M). FUT-175 protected against the Forssman shock at 1 mg/kg, i.v. and the in vitro immune hemolysis reaction at 10^-5M. In Type III, OKY-046 (300 mg/kg, p.o.) significantly suppressed the direct passive Arthus reaction and immune complex nephritis in rats. There was no effect of OKY-046 on the delayed-type hypersensitive response to picryl chloride in mice. We think that OKY-046 should be a beneficial drug for the treatment of types II and III allergic reactions.