title: A macrocyclic nitrosyl ruthenium complex is a NO donor that induces rat aorta relaxation.
abstract: The vasorelaxation induced by a nitrosyl macrocyclic ruthenium complex, proposed as a new nitric oxide (NO) carrier, was studied in rat isolated aorta. The compound trans-[RuCl([15]aneN4)NO]2+ was characterized by elemental analysis, UV-visible spectrum, and infrared spectrum. Based on the electrochemical process, the reduction of the compound was followed by NO release, which was also observed using norepinephrine as a reducing agent and NO released was analyzed by a sensor. Vasorelaxation induced by this NO donor was studied and compared to those obtained with sodium nitroprusside (SNP). The relaxation induced by the compound was concentration-dependent in denuded rat aortas and occurred only in pre-contracted arteries with norepinephrine. The macrocyclic compound induced relaxation with a similar efficacy as SNP, although the potency of SNP was slightly greater. The time to reach maximum relaxation (595 s) was longer than that of SNP (195 s). Relaxation was completely abolished by oxyhemoglobin, a known NO scavenger.
authors.affiliation: Laboratório de Farmacologia, Depto. de Física e Química, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, USP Av. do Café s/no, 14040-903 Ribeirão Preto, SP, Brazil.
authors.forename: Daniella
authors.initials: D
authors.lastname: Bonaventura
authors.forename: Fabiana
authors.initials: F
authors.lastname: de S Oliveira
authors.forename: Vanessa
authors.initials: V
authors.lastname: Togniolo
authors.forename: Antonio C
authors.initials: AC
authors.lastname: Tedesco
authors.forename: Roberto S
authors.initials: RS
authors.lastname: da Silva
authors.forename: Lusiane M
authors.initials: LM
authors.lastname: Bendhack
mesh_terms: D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects; D047028:Macrocyclic Compounds / Q000737:chemistry / Q000494:pharmacology; D008297:Male; D020030:Nitric Oxide Donors / Q000494:pharmacology*; D009599:Nitroprusside / Q000494:pharmacology; D009942:Organometallic Compounds / Q000737:chemistry / Q000494:pharmacology*; D010108:Oxyhemoglobins / Q000502:physiology; D011355:Prodrugs / Q000737:chemistry; D051381:Rats; D017975:Ruthenium Compounds / Q000737:chemistry / Q000494:pharmacology; D019789:Tetraethylammonium / Q000494:pharmacology; D014664:Vasodilation / Q000187:drug effects*
chemical_list: D047028:Macrocyclic Compounds; D020030:Nitric Oxide Donors; D009942:Organometallic Compounds; D010108:Oxyhemoglobins; D011355:Prodrugs; D017975:Ruthenium Compounds; C494411:chloronitrosyl(1,4,8,12-tetraazacyclopentadecane)ruthenium(III); D009599:Nitroprusside; D019789:Tetraethylammonium