Abstract
The effect of diethylnitrosamine (DEN), a well-known experimental carcinogen, toward MAO-A and MAO-B activity of rat liver was investigated. The oxidations of both β-PEA (MAO-B) and 5-HT (MAO-A) were inhibited by DEN. The Ki values of DEN in the inhibition of rat liver MAO-A and MAO-B activity were determined. The kinetic data show that DEN is a competitive, MAO-B selective inhibitor and its inhibitory effect on MAO-B is about 4-fold more potent than that on MAO-A. DEN might change the proportions of the multiple forms of MAO activity in tumor cells.
