The microsomal mixed-function oxidase system of Heliothis punctiger Wallengren and H. Armiger (Hübner) (Lepidoptera: Noctuidae)

Abstract

1. 1. The levels of cytochrome P-450, NADPH cytochrome c reductase, cytochrome b 5 and aldrin epoxidation revealed quantitative differences between H. armiger and H. punctiger and among the tissues (midgut, fatbody and integument) of each species. 2. 2. Qualitative differences between the species and among the tissues was indicated by P-450 spectral binding studies. Type I (substrate) binding occurred, in both species, only with midgut microsomes. Type II (ligand) binding occurred with n- octylamine in all tissues and with pyridine in only midgut and fatbody microsomes. Piperonyl butoxide added to reduced midgut microsomes illicited a type III spectrum. There was no reaction with either fatbody or integument microsomes. 3. 3. n- Octylamine difference spectra also revealed the presence of high-spin P-450 in the midgut microsomes of both species. Fatbody and integument P-450 were predominantly in the low-spin form.