Transfection of CYP4A1 cDNA increases vascular reactivity in renal interlobar arteries.
20-HETE, a cytochrome P-450 4A (CYP4A1)-derived arachidonic acid metabolite, is a major eicosanoid formed in renal and extrarenal microcirculation. 20-HETE inhibits Ca(2+)-activated K(+) channels in vascular smooth muscle cells and thereby may modulate vascular reactivity. We transfected renal interlobar arteries with an expression plasmid containing the cDNA of CYP4A1, the low-K(m) arachidonic acid omega-hydroxylase, and examined the consequences of increasing 20-HETE synthesis on constrictor responses to phenylephrine. CYP4A1-transfected interlobar arteries demonstrated a twofold increase in CYP4A protein levels and 20-HETE production compared with arteries transfected with the empty plasmid; they also showed increased sensitivity to phenylephrine, as evidenced by a decrease in EC(50) from 0.37 +/- 0.04 microM in plasmid-transfected arteries to 0.07 +/- 0.01 microM in CYP4A1-transfected arteries. The increased sensitivity to phenylephrine was greatly attenuated by N-methylsulfonyl-12,12-dibromododec-11-enamide (DDMS), a selective inhibitor of 20-HETE synthesis, and by 20-hydroxyeicosa-6(Z),15(Z)-dienoic acid, a specific 20-HETE antagonist. This effect of DDMS was reversed by addition of 20-HETE, further substantiating the notion that increased levels of 20-HETE contribute to the increased sensitivity to phenylephrine in vessels overexpressing CYP4A1. These data suggest that 20-HETE of vascular origin sensitizes renal vascular smooth muscle to phenylephrine.
Kaide
Jun-Ichi
J
Department of Pharmacology, New York Medical College, Valhalla 10595, USA.
Wang
Mong-Heng
MH
Wang
Ji-Shi
JS
Zhang
Fan
F
Gopal
V Raj
VR
Falck
John R
JR
Nasjletti
Alberto
A
Laniado-Schwartzman
Michal
M
D000577:Amides / Q000494:pharmacology; D000818:Animals; D016718:Arachidonic Acid / Q000378:metabolism; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics* / Q000378:metabolism*; D000072470:Cytochrome P450 Family 4; D018076:DNA, Complementary; D015870:Gene Expression / Q000502:physiology; D006893:Hydroxyeicosatetraenoic Acids / Q000378:metabolism; D008833:Microcirculation / Q000187:drug effects / Q000502:physiology; D010656:Phenylephrine / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012077:Renal Artery / Q000502:physiology*; D012079:Renal Circulation / Q000187:drug effects / Q000502:physiology; D013450:Sulfones / Q000494:pharmacology; D014162:Transfection; D014662:Vasoconstrictor Agents / Q000494:pharmacology
D000577:Amides; C465387:Cyp4a1protein, rat; D018076:DNA, Complementary; D006893:Hydroxyeicosatetraenoic Acids; D013450:Sulfones; D014662:Vasoconstrictor Agents; D010656:Phenylephrine; D016718:Arachidonic Acid; C055987:20-hydroxy-5,8,11,14-eicosatetraenoic acid; D003577:Cytochrome P-450 Enzyme System; C117975:DDMS; D000072470:Cytochrome P450 Family 4