A comparison of the effects of hexachlorobenzene, β‐naphthoflavone, and phenobarbital on cytochrome p‐450 and mixed‐function oxidases in Japanese quail

Abstract

Hexachlorobenzene (HCB), beta-naphthoflavone (BNF), or phenobarbital (PB) was administered to Japanese quail to determine their effects on hepatic porphyrin levels and drug-metabolizing enzymes. While HCB increased porphyrin levels, PB slightly reduced them, and BNF had no effect. HCB was an excellent inducer in quail, increasing the specific content of cytochrome P-450 to levels similar to those produced by BNF. Additional similarities between HCB- and BNF-treated quail included a comparable hypsochromic absorption shift in the CO-reduced difference spectra of cytochrome P-450 and similar effects on the activities of cytosolic glutathione S-transferase (GSH-t), biphenyl hydroxylase (BPH), and ethoxyresorufin O-deethylase (EROD). However, a differential response to HCB and BNF treatment was seen in the activities of hepatic NADPH-cytochrome P-450 reductase, epoxide hydrolase, GSH-t (microsomal), aryl hydrocarbon hydroxylase (AHH), and ethoxycoumarin O-deethylase (ECOD). The activities of NADPH-cytochrome P-450 reductase, AHH, and ECOD following treatment with HCB were similar to those found after dosing with PB. HCB caused a pattern of induction that was distinct from either BNF or PB and appeared to be a "mixed-type" inducer. The rapidity of the HCB-induced porphyrogenic response of Japanese quail, as compared to mammals, may provide unique advantages for making correlations between the in vivo metabolism of haloaromatic hydrocarbons and their effects on porphyrin metabolism.

Furazolidone induces the activity of microsomal enzymes that metabolize furazolidone in chickens

“…In the present study, the lack of effect of PB treatment on CPR activity in the chicken may be related to the bird-specific sensitivity of microsomal enzymes (including CPR) to PB [50]. Unlike humans or rats, little is known about the effect of β-NF and acetone on CPR in chickens, although β-NF and hexachlorobiphenyl (which is a potent inducer of CYP1 and CYP2B) significantly induced CPR activity in the Japanese quail.…”

“…Gupta et al [49] demonstrated that injection of PB (80 mg/kg, i.p., for 4 days) induced the activities of some CYP-related activities in adult hen livers, but did not refer to CPR. Additionally, in Japanese quails, injection of PB (70 mg or 150 mg/kg/day, i.p., for 5 days) resulted in a significant increase in CYP contents, but no change in the level of CPR [50].…”

“…Unlike humans or rats, little is known about the effect of β-NF and acetone on CPR in chickens, although β-NF and hexachlorobiphenyl (which is a potent inducer of CYP1 and CYP2B) significantly induced CPR activity in the Japanese quail. The inability to significantly induce the activity of CPR by treatment with β-NF in chickens could be attributed to inter-species differences [50].…”

Induction and quail liver diamine oxidase (histaminase). Part II: Different responses to the inducers

“…PB had less induction power in quails than in rats (see also [12]; CF increases all the measured microsomal activities after 14 days of treatment but was barely active at 7 days. The effect of inducers on DAO activity, measured using 14C-putrescine as substrate, is more easily understood considering the data of part I.…”

Induction of hepatic cytochrome p450 activities by toxaphene in rat and japanese quail

“…We have chosen to use the Japanese quail as a representative for a bird species because some information on hepatic P450 induction for this species is available. For instance, the induction of hepatic P450 activities after treatment of Japanese quail with other organochlorine contaminants [15,16], β‐naphthoflavone and pheno‐barbital [17,18], has been reported.…”