title: p38 Mitogen-activated protein kinase regulates vasoconstriction in spontaneously hypertensive rats.
abstract: We investigated whether p42/p44 mitogen-activated protein kinase (MAPK) and/or p38 MAPK participates in the regulation of vascular smooth muscle contraction by endothelin-1 (ET-1) in Wistar-Kyoto rat (WKY) and spontaneously hypertensive rat (SHR). ET-1 (10 nM) induced a sustained contraction in WKY and SHR aortas. PD98059 (100 microM), an inhibitor of p42/p44 MAPK kinase, partially attenuated the ET-1-induced contraction in WKY and SHR. However, SB203580 (10 microM), an inhibitor of p38 MAPK, relaxed the ET-1-induced contraction to the resting levels in SHR, but not in WKY. ET-1 (10 nM) increased phosphorylation of both p42/p44 MAPK and p38 MAPK in WKY and SHR. However, in SHR, p38 MAPK phosphorylation in response to ET-1 stimulation was increased more than in WKY. PD98059 (100 microM) and SB203580 (10 microM) abolished the phosphorylation of p42/p44 MAPK and p38 MAPK in response to ET-1 stimulation in WKY and SHR, respectively. On the other hand, SB203580 (10 microM) did not affect myosin light chain (MLC) phosphorylation in response to ET-1 (10 nM) stimulation in WKY and SHR. From these results, it is concluded that p42/p44 MAPK and/or p38 MAPK partially regulates the ET-1-induced vasoconstriction in WKY. However, p38 MAPK, rather than p42/p44 MAPK, activation plays an important role for the maintenance of ET-1-induced vasoconstriction in SHR through a MLC phosphorylation-independent pathway.
authors.affiliation: Department of Physiology, College of Medicine, Kwandong University, Kangnung, Korea.
authors.forename: Seongchun
authors.initials: S
authors.lastname: Kwon
authors.forename: Lian Hua
authors.initials: LH
authors.lastname: Fang
authors.forename: Bokyung
authors.initials: B
authors.lastname: Kim
authors.forename: Tae-Seon
authors.initials: TS
authors.lastname: Ha
authors.forename: Sang Jin
authors.initials: SJ
authors.lastname: Lee
authors.forename: Hee Yul
authors.initials: HY
authors.lastname: Ahn
mesh_terms: D000818:Animals; D019332:Endothelin-1 / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology; D006973:Hypertension / Q000503:physiopathology*; D007093:Imidazoles / Q000494:pharmacology; D019950:Mitogen-Activated Protein Kinase 1 / Q000502:physiology; D048052:Mitogen-Activated Protein Kinase 3 / Q000502:physiology; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D018994:Myosin Light Chains / Q000378:metabolism; D010766:Phosphorylation; D011725:Pyridines / Q000494:pharmacology; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D014661:Vasoconstriction / Q000502:physiology*; D048051:p38 Mitogen-Activated Protein Kinases / Q000502:physiology*
chemical_list: D019332:Endothelin-1; D004791:Enzyme Inhibitors; D005419:Flavonoids; D007093:Imidazoles; D018994:Myosin Light Chains; D011725:Pyridines; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D048051:p38 Mitogen-Activated Protein Kinases; C093642:SB 203580; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one