title: Possible mediators involved in decreasing peripheral vascular resistance with blackcurrant concentrate (BC) in hind-limb perfusion model of the rat.
abstract: We analyzed mechanisms decreasing hind-limb perfusion pressure (PP) with blackcurrant concentrate (BC) in the rat. The decrease in PP with BC was abolished by endothelial removal, nitroarginine plus tetraethylammonium, nitroarginine plus catalase or 1H-[1,2,4]oxadiazolo[4,3-a]quinoxaline-1-one as an inhibitor of guanylyl cyclase and potassium channel(s), and accompanied by the increased cyclic GMP level. Partial but significant inhibition caused by KCl was observed during contraction. Authentic H2O2 decreased the PP in a sensitive manner to catalase and tetraethylammonium. The decrease in PP with BC in the presence of nitroarginine was significantly attenuated by diverse potassium channel blockers. Two delphinidins of 4 anthocyanins purified from BC definitely decreased the PP through similar mechanisms to BC. These results suggest that the decreased PP with BC is possibly mediated by endothelial NO and H2O2, and partially through the activation of diverse potassium channels, and that 2 delphinidins play a major role as active components of BC.
authors.affiliation: Department of Biosystem Regulation, Institute of Biomaterials and Bioengineering, Graduate School, Tokyo Medical and Dental University, Chiyoda-ku, Tokyo 101-0062, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Iwasaki-Kurashige
authors.forename: Renzo Y
authors.initials: RY
authors.lastname: Loyaga-Rendon
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Matsumoto
authors.forename: Takahisa
authors.initials: T
authors.lastname: Tokunaga
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Azuma
mesh_terms: D015761:4-Aminopyridine / Q000494:pharmacology; D000818:Animals; D000872:Anthocyanins / Q000302:isolation & purification / Q000494:pharmacology; D002374:Catalase / Q000494:pharmacology; D006152:Cyclic GMP / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005638:Fruit; D006614:Hindlimb; D006861:Hydrogen Peroxide / Q000378:metabolism / Q000494:pharmacology; D018482:Muscle, Skeletal / Q000098:blood supply / Q000187:drug effects* / Q000201:enzymology; D009569:Nitric Oxide / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D019335:Nitroarginine / Q000494:pharmacology; D010477:Perfusion; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D026902:Potassium Channel Blockers / Q000494:pharmacology; D015221:Potassium Channels / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D031965:Ribes; D014655:Vascular Resistance
chemical_list: D000872:Anthocyanins; D004791:Enzyme Inhibitors; D010936:Plant Extracts; D026902:Potassium Channel Blockers; D015221:Potassium Channels; D019335:Nitroarginine; D009569:Nitric Oxide; D006861:Hydrogen Peroxide; D015761:4-Aminopyridine; D002374:Catalase; D019001:Nitric Oxide Synthase; D006152:Cyclic GMP