RESUMO
BACKGROUND: Arachidonic acid (AA) is oxidized by cytochrome P450s (CYPs) to form epoxyeicosatrienoic acids (EETs), compounds that modulate ion transport, gene expression, and vasorelaxation. Both CYP2Cs and CYP2Js are involved in kidney EET epoxidation. METHODS: In this study, we used a CYP2C11-null rat model to explore the in vivo effects of CYP2C11 on vasorelaxation. For 2 months, CYP2C11-null and wild-type (WT) Sprague-Dawley rats were either fed normal lab (0.3% (w/w) sodium chloride) or high-salt (8% (w/w) sodium chloride) diets. Subsequently, an invasive method was used to determine blood pressure. Next, western blots, quantitative PCR, and immunohistochemistry were used to determine renal expression of CYPs involved in AA metabolism. RESULTS: Among CYP2C11-null rats, a high-salt diet (females: 156.79 ± 15.89 mm Hg, males: 130.25 ± 16.76 mm Hg, n = 10) resulted in significantly higher blood pressure than a normal diet (females: 118.05 ± 8.43 mm Hg, P < 0.01; males: 115.15 ± 11.45 mm Hg, P < 0.05, n = 10). Compared with WT rats under the high-salt diet, western blots showed that CYP2C11-null rats had higher renal expression of CYP2J2 and CYP4A. This was consistent with the results of immunohistochemistry and the qPCR, respectively. The two rat strains did not differ in the renal expression of CYP2C23 or CYP2C24. CONCLUSION: Our findings suggested that CYP2C11 plays an important role in lowering blood pressure under the challenge of a high-salt diet.
RESUMO
1. CYP2C11 is the most abundant isoform of cytochrome P450s (CYPs) in male rats and is considered the main enzyme for warfarin metabolism. 2. To further access the in vivo function of CYP2C11 in warfarin metabolism and efficacy, a CYP2C11-null rat model was used to study warfarin metabolism with both in vitro and in vivo approaches. Prothrombin time (PT) of warfarin was also determined. 3. The maximum rate of metabolism (Vmax) and intrinsic clearance (CLint) of liver microsomes from CYP2C11-null males were reduced by 37 and 64%, respectively, compared to those in Sprague Dawley (S-D) rats. The Km of liver microsomes from CYP2C11-null males was increased by 73% compared to that of S-D rats. The time to reach the maximum plasma concentration (Tmax) of warfarin in CYP2C11-null males was significantly delayed compared to that in S-D males, and the CL rate was also reduced. The PT of CYP2C11-null rats was moderately longer than that of S-D rats. 4. In conclusion, the clearance rate of warfarin was mildly decreased and its anticoagulant effect was moderately increased in male rats following CYP2C11 gene knockout. CYP2C11 played a certain role in the clearance and efficacy of warfarin, while it did not seem to be essential.
