Selective downregulation of hepatic cytochrome P450 expression and activity in a rat model of inflammatory pain.

Purpose: This study was designed to examine the effect of Freund's complete adjuvant (FCA)-induced inflammation on liver P450 expression and activities in the first 7 days that followed a single FCA injection in the rat hindpaw.

Methods: Rats were humanely sacrificed at regular time points, plasma and liver samples were collected, liver mRNA extracted, and liver microsomes prepared.

Results: FCA injection led to the development of an acute inflammatory response evidenced by paw edema and increased alpha-1-acid glycoprotein (AGP) and total-nitrite (NOx) plasma concentrations.