Some biological effects of calvatic acid and its analog on isolated hepatocytes.

Calvatic acid is a new antibiotic with both a carboxylic group and an azoxy function in the benzene ring. The relationship between structure and biological activity in this substance and one of its analog, phenylazoxyxyanide, was investigated. Isolated hepatocytes were used as an experimental system: the release of lactate dehydrogenase and the colchicine-binding activity of tubulin were first evaluated; effects were dose and time dependent. micromolar concentrations of these drugs determined a significant decrease of the glucose-6-phosphatase activity and a slight inhibition of aminopyrene demethylation. A toxic effect at the microsomal level and an interaction with the microtubular system are thus possible.