Azo- and Nitro-reductase Activities and Cytochromes of Ascaris lumbricoides var suum and Moniezia expansa

Abstract

1. Isoelectric focusing failed to separate the azo- and nitro-reductases in enzyme preparations from either the nematode Ascaris lumbricoides var suum or the cestode Moniezia expansa. The isoelectric point of the reductases from A. lumbricoides var suum was 4–75, and that of the reductases from M. expansa, 4–50.

2. Cytochromes P-450 and b₅ were not detected in the 100 000 g pellet of tissue homogenates from either A. lumbricoides var suum or M. expansa. These cytochromes were not induced in either helminth by 20-methylcholanthrene or 1,2-benzanthracene.

3. The absence of cytochromes P-450 and b₅ from A. lumbricoides var suum and M. expansa may be the reason for their inability to metabolize drugs by oxidative pathways and for the 100 000 g pellets of their tissue homogenates being unable to reduce azo- or nitro-compounds.