1. Effects of carbon monoxide on trout and lamprey vessels.
- Author
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Dombkowski RA, Whitfield NL, Motterlini R, Gao Y, and Olson KR
- Subjects
- Animals, Aorta drug effects, Aorta metabolism, Branchial Region blood supply, Dose-Response Relationship, Drug, Enzyme Inhibitors pharmacology, Glyburide pharmacology, Guanylate Cyclase antagonists & inhibitors, Guanylate Cyclase metabolism, Heme Oxygenase (Decyclizing) antagonists & inhibitors, Heme Oxygenase (Decyclizing) metabolism, Hydrogen Sulfide metabolism, Muscle, Smooth, Vascular metabolism, Myography, Nitric Oxide metabolism, Nitroprusside pharmacology, Norepinephrine pharmacology, Oxadiazoles pharmacology, Oxazines pharmacology, Polarography, Potassium Channel Blockers pharmacology, Potassium Chloride pharmacology, Protoporphyrins pharmacology, Receptors, Cytoplasmic and Nuclear antagonists & inhibitors, Receptors, Cytoplasmic and Nuclear metabolism, Soluble Guanylyl Cyclase, Vasoconstrictor Agents pharmacology, Carbon Monoxide metabolism, Muscle, Smooth, Vascular drug effects, Oncorhynchus mykiss metabolism, Organometallic Compounds pharmacology, Petromyzon metabolism, Vasodilation drug effects, Vasodilator Agents pharmacology
- Abstract
Carbon monoxide (CO) is endogenously produced by heme oxygenase (HO) and is involved in vascular, neural, and inflammatory responses in mammals. However, the biological activities of CO in nonmammalian vertebrates is unknown. To this extent, we used smooth muscle myography to investigate the effects of exogenously applied CO (delivered via a water-soluble CO-releasing molecule, CORM-3) on isolated lamprey (Petromyzon marinus) dorsal aortas and examined its mechanisms of action on trout (Oncorhynchus mykiss) efferent branchial (EBA) and celiacomesenteric (CMA) arteries. CORM-3 dose-dependently relaxed all vessels examined. Trout EBA were twofold more sensitive to CORM-3 when precontracted with norepinephrine (NE) than KCl and CORM-3 relaxed five-fold more of the NE- than KCl-induced tension. Glybenclamide (10 microM), an ATP-sensitive potassium channel inhibitor, inhibited NE-induced contraction, but did not affect CORM-3-induced relaxation. NS-2028 (10 microM), a soluble guanylyl cyclase inhibitor, had no effect on a NE-contraction, but inhibited a subsequent CORM-3-induced relaxation. Zinc protopophyrin-IX (ZnPP-IX, 0.3-30 microM), a HO inhibitor, elicited a small, yet dose-dependent and significant, increase in baseline tension but did not have any effect on subsequent NE-induced contractions or a nitric oxide-induced relaxation (via sodium nitroprusside). [ZnPP-IX] greater than 3 microM, however, significantly reduced the predominant vasodilatory response of trout EBA to hydrogen sulfide. These results implicate an active HO/CO pathway in trout vessels having an impact on resting vessel tone and CO-induced vasoactivity that is at least partially mediated by soluble guanylyl cyclase.
- Published
- 2009
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