Contraction of arterial smooth muscle of normotensive and spontaneously hypertensive rats by manganese(III)tetrakis(1-methyl-4-pyridyl)porphyrin (MnTMPyP).
Manganese(III)tetrakis(1-methyl-4-pyridyl)porphyrin (MnTMPyP), which has been known as a cell permeable superoxide dismutase mimetic, induced concentration-dependent contraction in rat carotid artery acting directly on smooth muscle. The contractile action was more prominent in the preparation from stroke-prone spontaneously hypertensive rats (SHRSP) compared with that from Wistar Kyoto rats (WKY). It was abolished by the removal of extracellular Ca(2+) or the application of verapamil. These results suggest that the MnTMPyP-induced contraction is brought about by Ca(2+) influx through voltage-dependent Ca(2+) channels (VDCC) and that the difference in VDCC is the cause of the difference in MnTMPyP action between preparations from WKY and SHRSP.
Sekiguchi
Fumiko
F
Department of Anatomy and Physiology, School of Pharmaceutical Sciences, Kinki University, Osaka, Japan. fumiko@phar.kindai.ac.jp
Seo
Mikako
M
Sunano
Satoru
S
D000818:Animals; D002339:Carotid Arteries / Q000187:drug effects* / Q000502:physiology; D006973:Hypertension / Q000503:physiopathology; D066298:In Vitro Techniques; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D008665:Metalloporphyrins / Q000494:pharmacology*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D014661:Vasoconstriction / Q000187:drug effects* / Q000502:physiology
D008665:Metalloporphyrins; C050950:tetrakis(N-methyl-4-pyridiniumyl)porphine manganese(III) complex