Abstract

The effect of m-xylene on the rat nasal cytochrome P450 (P450) mixed function oxidase system was analyzed in vitro utilizing microsomes isolated 2, 12, and 24 h following intraperitoneal administration of this solvent in vivo. For comparative purposes, pulmonary and hepatic activities were also measured. Benzyloxyresorufin O-deethylation (BROD) and ethoxyresorufin O-deethylation (EROD), catalytic activities linked with P450 isozymes IIB1 and IA1, respectively, were inhibited in nasal tissue at all times following m-xylene administration. Pulmonary tissue mimicked this m-xylene-dependent inhibition of BROD activity but did not display significant inhibition of EROD activity. In contrast, m-xylene caused a dramatic induction of both BROD and EROD activity in hepatic tissue. The metabolism of a third P450 substrate, cyclopentadienyl manganese tricarbonyl (CMT), was also analyzed. m-Xylene caused significant inhibition of CMT metabolism at all time points in both nasal and pulmonary microsomes but was without effect on hepatic microsomal metabolism of this compound. These data show an inhibitory effect of m-xylene on rat nasal and pulmonary but not hepatic cytochrome P450-dependent metabolism.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.