TY - JOUR
T1 - Mixed-function oxygenation of the lower fatty acyl residues. II. The kinetics of microsomal omega- and (omega - 1)-hydroxylation of N-(4-chlorophenyl)propanamide.
JF - Drug Metabolism and Disposition
JO - Drug Metab Dispos
SP - 315
LP - 321
VL - 9
IS - 4
AU - Apostolescu, V
AU - Lenk, W
Y1 - 1981/07/01
UR - http://dmd.aspetjournals.org/content/9/4/315.abstract
N2 - Investigation of the kinetics of microsomal omega- and (omega - 1)-hydroxylation of 4,'-chloropropionanilide with rabbit liver microsomes revealed normal Michaelis-Menten behavior for that form of cytochrome P-450 which catalyzes omega-hydroxylation, and deviation from Michaelis-Menten behavior for the form(s) of the hemoprotein that catalyze(s) (omega - 1)-hydroxylation. This is deduced from linear Lineweaver-Burk plots of the kinetic data from omega-hydroxylation and from concavely curved downward plots of the kinetic data from (omega - 1)-hydroxylation. Evaluation of the apparent kinetic constants for (omega - 1)-hydroxylation was achieved by means of a computer program developed on the basis of non-linear regression analysis. The effect of inducers of microsomal oxygenases, such as phenobarbital and 3-methylcholanthrene, and of modifiers of microsomal enzyme activities, such as NADH, EDTA, nicotinamide, and SKF 525-A on the kinetics of omega- and (omega - 1)-hydroxylation has been studied. The two types of hydroxylation were affected differently, and different concentrations of the modifiers affected the hydroxylation pattern differently.
ER -