3‐Methylcholanthrene and benzo(a)pyrene modulate cardiac cytochrome P450 gene expression and arachidonic acid metabolism in male Sprague Dawley rats

Abstract

Background and purpose:There is a strong correlation between cytochrome P450 (P450)-dependent arachidonic acid metabolism and the pathogenesis of cardiac hypertrophy. Several aryl hydrocarbon receptor (AhR) ligands were found to alter P450-dependent arachidonic acid metabolism. Here, we have investigated the effect of 3-methylcholanthrene (3-MC) and benzo(a)pyrene (BaP), two AhR ligands, on the development of cardiac hypertrophy. Experimental approach: Male Sprague Dawley rats were injected (i.p.) daily with either 3-MC (10 mg·kg ) for 7 days. Then hearts were removed, and the heart to body weight ratio and the gene expression of the hypertrophic markers and P450 genes were determined. Levels of arachidonic acid metabolites were determined by liquid chromatography-electron spray ionization-mass spectrometry. Key results: Both 3-MC and BaP increased the heart to body weight ratio as well as the hypertrophic markers, atrial natriuretic peptide and brain natriuretic peptide. 3-MC and BaP treatment increased the gene expression of CYP1A1, CYP1B1, CYP2E1, CYP4F4, CYP4F5 and soluble epoxide hydrolase. Both 3-MC and BaP treatments increased the dihydroxyeicosatrienoic acids (DHETs) : epoxyeicosatrienoic acids (EETs) ratio and the 20-hydroxyeicosatetraenoic acid (20-HETE) : total EETs ratio. Treatment with benzo(e)pyrene, an isomer of BaP that is a poor ligand for the AhR, did not induce cardiac hypertrophy in rats, confirming the role of AhR in the development of cardiac hypertrophy. Treatment with the w-hydroxylase inhibitor, HET0016, significantly reversed BaP-induced cardiac hypertrophy. Conclusions and implications: 3-MC and BaP induce cardiac hypertrophy by increasing the ratio of DHETs : EETs and/or the ratio of 20-HETE : total EETs, through increasing soluble epoxide hydrolase activity.

Determination of the Dominant Arachidonic Acid Cytochrome P450 Monooxygenases in Rat Heart, Lung, Kidney, and Liver: Protein Expression and Metabolite Kinetics

“…On the other hand, 20-HETE is reported to be a potent vasoconstrictor (10) and has been shown to play a role in several pathological heart conditions, including cardiac hypertrophy (11)(12)(13). Renal 20-HETE levels are increased in the spontaneously hypertensive rat model of essential hypertension (14).…”

Acute Doxorubicin Toxicity Differentially Alters Cytochrome P450 Expression and Arachidonic Acid Metabolism in Rat Kidney and Liver

“…Microsomal protein was prepared from kidney and liver tissues as described previously (Aboutabl et al, 2009). In brief, kidney and liver tissues were washed in ice-cold KCl (1.15% w/v), cut into pieces, and homogenized separately in cold sucrose solution (1 g of tissue in 5 ml of 0.25 M sucrose).…”

Chronic Doxorubicin Cardiotoxicity Modulates Cardiac Cytochrome P450-Mediated Arachidonic Acid Metabolism in Rats

“…After adding the acetonitrile, the supernatant was extracted twice with 1 ml of ethyl acetate and dried using speed vacuum (Thermo Fisher Scientific). The LC-ESI-MS (Waters Micromass ZQ 4000 spectrometer; Waters, Milford, MA) method was used to analyze extracted AA metabolites as described previously (Aboutabl et al, 2009). In brief, the mass spectrometer was used in negative mode with single ion recorder acquisition.…”

“…Microsomal protein was prepared from the heart tissues as described previously (Aboutabl et al, 2009). In brief, heart tissues were washed in ice-cold KCl (1.15%, w/v), cut into pieces, and homogenized separately in ice-cold sucrose solution (1 g of tissue in 5 ml of 0.25 M sucrose).…”