title: Use of nitric oxide-nucleophile adducts as biological sources of nitric oxide: effects on airway smooth muscle.
abstract: Nitric oxide (NO)-nucleophile adducts are compounds of the general structure [XN(O)NO]-, where X is a nucleophile residue, and they release NO spontaneously in aqueous solution. This study determined the effects of two NO-nucleophile adducts [diethylaminodiazen-1-ium-1,2-diolate (DEA-NO) and sperminediazen-1-ium-1,2-diolate (DEA-NO) and sperminediazen-1-ium-1,2-diolate (spermine-NO)] on isometric force and the cytosolic concentrations of cyclic GMP ([cGMP]1), cyclic AMP ([cAMP]i) and calcium in canine tracheal smooth muscle. The ratio of fura-2 emission fluorescence intensities with excitation at 340- and 380-nm wavelengths (F340/ F380) was used as an index of cytosolic [Ca+2] concentration. Both DEA-NO and spermine-NO caused a concentration-dependent and reversible decrease in force (EC50 of 0.13 +/- 0.02 microM and 4.1 +/- 0.3 microM, respectively) and F340/F380, a concentration-dependent increase in [cGMP]i and no change in [cAMP]i. There were no significant differences in the relationship between [cGMP]l and the percentage decrease in force or in the relationship between the percentage decrease in F340/ F380 and the percentage decrease in force between tissues relaxed with DEA-NO or spermine-NO. Oxyhemoglobin increased the EC50 for both DEA-NO (from 0.13 +/- 0.03 microM to 8.1 +/- 0.2 microM) and spermine-NO (from 3.9 +/- 0.3 microM to 81.6 +/- 6.4 microM) and completely scavenged NO released by 0.13 (EC50) and 1 (EC100)microM DEA-NO. These results suggest that both DEA-NO and spermine-NO generate NO extracellularly and relax airway smooth muscle in association with an increase in [cGMP]i and a decrease in cytosolic Ca+2 concentration. NO-nucleophile adducts may serve as vehicles for the controlled delivery of NO into biological systems and thus provide a useful tool by which the physiology of NO can be investigated.
authors.affiliation: Department of Anesthesiology, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: A
authors.initials: A
authors.lastname: Hirasaki
authors.forename: K A
authors.initials: KA
authors.lastname: Jones
authors.forename: W J
authors.initials: WJ
authors.lastname: Perkins
authors.forename: D O
authors.initials: DO
authors.lastname: Warner
mesh_terms: D000818:Animals; D000242:Cyclic AMP / Q000378:metabolism; D006152:Cyclic GMP / Q000378:metabolism; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D005260:Female; D006834:Hydrazines / Q000008:administration & dosage*; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009126:Muscle Relaxation / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D009465:Neuromuscular Agents / Q000494:pharmacology; D009569:Nitric Oxide / Q000008:administration & dosage*; D009589:Nitrogen Oxides; D010108:Oxyhemoglobins / Q000378:metabolism; D013096:Spermine / Q000008:administration & dosage / Q000031:analogs & derivatives*; D014132:Trachea / Q000187:drug effects
chemical_list: D006834:Hydrazines; D009465:Neuromuscular Agents; D009589:Nitrogen Oxides; D010108:Oxyhemoglobins; C091861:spermine nitric oxide complex; D013096:Spermine; D009569:Nitric Oxide; C084012:1,1-diethyl-2-hydroxy-2-nitrosohydrazine; D000242:Cyclic AMP; D006152:Cyclic GMP