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CYP2C7 is an EET synthase in arteriolar endothelium of NO deficient female rats
Author(s) -
Huang An,
Sun Dong,
Kaley Gabor
Publication year - 2011
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.25.1_supplement.643.3
We aimed to identify which specific gene(s) of the P450 family accounts for the EET synthesis in arterioles of rats. A rat P450 cDNA Plate Array that profiles the expression of 32 genes of the CYP450 family, was used in mesenteric arterioles (~150–200 μm in diameter) isolated from male and female rats that had been treated with L‐NAME (50mg/100 ml drinking water) for 3–4 weeks. The array revealed a specific upregulation of CYP2C7 (more than 2 fold) in vessels of female compared to male rats. There was no difference in expression of other endothelial CYP genes, including 2C11, 2C13, 2C23 and 2J3, between male and female rats, indicating a gender‐specific regulation of 2C7. To validate the results obtained from cDNA plate array, endothelial RNA was extracted from single arteries, followed by real time PCR. Our PCR analysis is the first to demonstrate the expression of CYP2C7 in vascular endothelium of rats. The functional significance of endothelial 2C7 was evaluated by measurement of shear stress (SS)‐stimulated EETs in vessels. Cannulated mesenteric arteries isolated from L‐NAME treated female rats were perfused with 2 and 10 dyne/cm 2 SS for 5 minutes, followed by collection of the perfusate to measure EETs by GC‐MS. SS stimulated the release of EETs into the perfusate, in a concentration of 9.3 ± 2.7 (SS=2 dyne/cm 2 ) and 69.9 ± 15.0 (SS=10 dyne/cm 2 ) pg/min/mm 2 intraluminal surface area of the vessel, respectively. The response was prevented by PPOH, an inhibitor of EET synthase, and eliminated by CYP2C7 siRNA. To characterize specific regioisomers of EETs detected in the perfusate, collected samples were pooled after purification of EETs, followed by LC‐MS analysis. We demonstrated that 11,12‐ and 14,15‐EETs contribute a larger share of EETs released (42.9 % and 34.0 %), whereas, 8,9‐ and 5,6‐EETs make a lesser contribution (16.6 % and 6.5 %). Thus, CYP2C7 is the EET synthase in arteriolar endothelium of NO deficient female rats. (Supported by NIH HL070653 and HL43023).