Abstract
The effect of diphenylhydantoin on LD 50 of ouabain was investigated in frogs, using "one hour frog method".
LD50 of ouabain in control group was 1.90 µg/10g.
A dose of 100 µg/10g diphenylhydantion did not affect the systemic manifestations of the frogs, but increase the LD50 of ouabain to 2.60 µg/10g.
The difference of LD50 of ouabain and potency ratio between control group and diphenylhydantoin-treated group was statistically significant.