Various factors influencing monoamine oxidase activities of mitochondria obtained from rat erebral cortex were investigated. These factors included pH and temperature of incubation media, ln16ns, divalent cations, hydrogen peroxide, sulfhydryl inhibitor, compounds containing SH groups nd sonication.
{ With kynuramine, the maximum MAO activity was observed at the concentration of O.1mM kid increasing the concentratin beyond 0.1mM was accompained by a decrease in the enzyme ac tvtty. The MAO activity was considerably altered by change of the pH of the incubation medium
!pd the maximum value was observed at pH 8.0. MAO was resistant to temperature of incubation
r nedium and the activity was not significantly affected at the temperature range of OC -37C, but hereafter the activity was decreased with temperature, Among anions and cations tested, sulfite
Pn, Ag++, Cu" and Cd++ markedly inhibited MAO activity. Specific inhibitors for SH group such ;s, HgC12, PCMI3 and PGMBSA significantly inhibited MAO activity. Inhibitory action of Hg++ vas reversed by cysteine, GSH and MPG. Hydrogen peroxide weakly inhibited the MAO activity. 4A0 activity was decreased by sonication.
The results suggest that factors influencing the cellular environment can alter MAO´ activity.
|