Enhancement of hepatic microsomal aniline hydroxylation by Habu snake (Trimeresurus flavoviridis) venom fractions.

Enhancement of aniline hydroxylation by Habu snake venom was studied in vitro. The fraction which was isolated from Habu venom through column chromatography caused the enhancement of aniline hydroxylation of hepatic microsomes obtained from untreated rats. This fraction was heat stable and free from phospholipase activity. Enhancement of aniline hydroxylation was not clear in crude Habu venom or the unheated fraction, but appeared after heating of the fraction. This fraction enhanced aniline hydroxylation at low concentrations, followed by inhibition at high concentrations, but inhibited aminopyrine N-demethylation dose-dependently. Aniline hydroxylation was enhanced by the heated fraction at more than 1 mM aniline, and the enhancement was rather decreased at more than 10 mM aniline. The degree of the enhancement by the heated fraction increased with increasing pH.