title: Decreased CYP3A expression and activity in guinea pig models of diet-induced metabolic syndrome: is fatty liver infiltration involved?
abstract: BACKGROUND
  In humans, CYP3A drug-metabolizing enzyme subfamily is the most important. Numerous pathophysiological factors, such as diabetes and obesity, were shown to affect CYP3A activity. Often considered a precursor state for type II diabetes, metabolic syndrome exerts a modulating role on CYP3A, in our hypothesis.
  
  
  OBJECTIVE
  To evaluate the effect of metabolic syndrome on CYP3A drug-metabolizing activity/expression in guinea pigs.
  
  
  METHODS
  Hepatic microsomes were prepared from male Hartley guinea pigs fed with a control, a high-fat high sucrose (HFHS) or a high-fat high fructose diet (HFHF). Domperidone was selected as a probe substrate of CYP3A and formation of four of its metabolites was evaluated using high-performance liquid chromatography. CYP3A protein and mRNA expression were assessed by Western blot and reverse-transcription quantitative polymerase chain reaction, respectively. Hepatic fatty infiltration was evaluated using standard Oil Red O staining. Triglyceride and free fatty acid liver content were also quantified.
  
  
  RESULTS
  Microsomal CYP3A activity was significantly decreased in both HFHS and HFHF diet groups versus the control diet group. Significant decreases of CYP3A mRNA and protein expression were observed in both HFHS and HFHF diet groups. Oil Red O staining showed a massive liver fatty infiltration in the HFHS and HFHF diet groups, which was not observed in the control diet group. Both triglyceride and free fatty acid liver content were significantly increased in the HFHS and HFHF diet groups.
  
  
  CONCLUSIONS
  Diet-induced metabolic syndrome decreases CYP3A expression/activity in guinea pigs. This may ultimately lead to variability in drug response, ranging from lack of effect to life-threatening toxicity.
authors: Institut Universitaire de Cardiologie et de Pneumologie de Québec, Québec City, Québec, Canada.
authors: Dany
authors: D
authors: Patoine
authors: Xavier
authors: X
authors: Levac
authors: Sylvie
authors: S
authors: Pilote
authors: Benoit
authors: B
authors: Drolet
authors: Chantale
authors: C
authors: Simard
mesh_terms: D000818:Animals; D051544:Cytochrome P-450 CYP3A / Q000378:metabolism*; D004195:Disease Models, Animal; D005234:Fatty Liver / Q000150:complications*; D006168:Guinea Pigs; D006801:Humans; D008297:Male; D024821:Metabolic Syndrome / Q000201:enzymology* / Q000209:etiology; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D051544:Cytochrome P-450 CYP3A; C510163:CYP3A4 protein, human