title: Transfection of CYP4A1 cDNA decreases diameter and increases responsiveness of gracilis muscle arterioles to constrictor stimuli.
abstract: Cytochrome P-450-4A1 (CYP4A1) is an omega-hydroxylase that catalyzes the metabolism of arachidonic acid to 20-hydroxyeicosatetraenoic acid (20-HETE). The goal of this study was to determine the vasomotor consequences of vascular overexpression of CYP4A1. Isolated rat gracilis muscle arterioles transfected ex vivo with an expression plasmid containing CYP4A1 cDNA expressed more CYP4A protein than vessels transfected with the control plasmid. In arterioles pressurized to 80 mmHg, the internal diameter of vessels transfected with CYP4A1 cDNA (55 +/- 3 microm) was surpassed (P < 0.05) by that of vessels transfected with control plasmid (97 +/- 4 microm). Treatment with a CYP4A inhibitor (N-methylsulfonyl-12,12-dibromododec-11-enamide; DDMS) or with an antagonist of 20-HETE actions [20-hydroxyeicosa-6(Z),15(Z)-dienoic acid; 20-HEDE] elicited robust dilation of arterioles transfected with CYP4A1 cDNA, whereas the treatment had little or no effect in vessels transfected with control plasmid. Examination of the intraluminal pressure-internal diameter relationship revealed that pressure increments over the range of 40-100 mmHg elicited a more intense (P < 0.05) myogenic constrictor response in arterioles transfected with CYP4A1 cDNA than in those with control plasmid. Arterioles transfected with CYP4A1 cDNA also displayed enhanced sensitivity to the constrictor action of phenylephrine. Treatment with DDMS or 20-HEDE greatly attenuated the constrictor responsiveness to both constrictor stimuli in vessels overexpressing CYP4A1, whereas the treatment had much less effect in control vessels. These data suggest that CYP4A1 overexpression promotes constriction of gracilis muscle arterioles by intensifying the responsiveness of vascular smooth muscle to constrictor stimuli. This effect of CYP4A1 overexpression appears to be mediated by a CYP4A1 product.
authors.affiliation: Department of Pharmacology, New York Medical College, Valhalla, New York 10595, USA. Fan_Zhang@nymc.edu
authors.forename: Fan
authors.initials: F
authors.lastname: Zhang
authors.forename: Mong-Heng
authors.initials: MH
authors.lastname: Wang
authors.forename: Ji-Shi
authors.initials: JS
authors.lastname: Wang
authors.forename: Barbara
authors.initials: B
authors.lastname: Zand
authors.forename: V Raj
authors.initials: VR
authors.lastname: Gopal
authors.forename: John R
authors.initials: JR
authors.lastname: Falck
authors.forename: Michal
authors.initials: M
authors.lastname: Laniado-Schwartzman
authors.forename: Alberto
authors.initials: A
authors.lastname: Nasjletti
mesh_terms: D000577:Amides / Q000494:pharmacology; D000818:Animals; D001160:Arterioles / Q000187:drug effects* / Q000502:physiology; D065607:Cytochrome P-450 Enzyme Inhibitors; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics* / Q000378:metabolism; D000072470:Cytochrome P450 Family 4; D018076:DNA, Complementary; D006893:Hydroxyeicosatetraenoic Acids / Q000037:antagonists & inhibitors; D066298:In Vitro Techniques; D008297:Male; D018482:Muscle, Skeletal / Q000098:blood supply*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D010656:Phenylephrine / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013450:Sulfones / Q000494:pharmacology; D014162:Transfection; D014661:Vasoconstriction; D014662:Vasoconstrictor Agents / Q000494:pharmacology*
chemical_list: D000577:Amides; C465387:Cyp4a1protein, rat; D065607:Cytochrome P-450 Enzyme Inhibitors; D018076:DNA, Complementary; D006893:Hydroxyeicosatetraenoic Acids; D013450:Sulfones; D014662:Vasoconstrictor Agents; D010656:Phenylephrine; C055987:20-hydroxy-5,8,11,14-eicosatetraenoic acid; D003577:Cytochrome P-450 Enzyme System; C117975:DDMS; D000072470:Cytochrome P450 Family 4