title: Nitroglycerin-induced S-nitrosylation and desensitization of soluble guanylyl cyclase contribute to nitrate tolerance.
abstract: Nitrates such as nitroglycerin (GTN) and nitric oxide donors such as S-nitrosothiols are clinically vasoactive through stimulation of soluble guanylyl cyclase (sGC), which produces the second messenger cGMP. Development of nitrate tolerance, after exposure to GTN for several hours, is a major drawback to a widely used cardiovascular therapy. We recently showed that exposure to nitric oxide and to S-nitrosothiols causes S-nitrosylation of sGC, which directly desensitizes sGC to stimulation by nitric oxide. We tested the hypothesis that desensitization of sGC by S-nitrosylation is a mechanism of nitrate tolerance. Our results established that vascular tolerance to nitrates can be recapitulated in vivo by S-nitrosylation through exposure to cell membrane-permeable S-nitrosothiols and that sGC is S-nitrosylated and desensitized in the tolerant, treated tissues. We next determined that (1) GTN treatment of primary aortic smooth muscle cells induces S-nitrosylation of sGC and its desensitization as a function of GTN concentration; (2) S-nitrosylation and desensitization are prevented by treatment with N-acetyl-cysteine, a precursor of glutathione, used clinically to prevent development of nitrate tolerance; and (3) S-nitrosylation and desensitization are reversed by cessation of GTN treatment. Finally, we demonstrated that in vivo development of nitrate tolerance and crosstolerance by 3-day chronic GTN treatment correlates with S-nitrosylation and desensitization of sGC in tolerant tissues. These results suggest that in vivo nitrate tolerance is mediated, in part, by desensitization of sGC through GTN-dependent S-nitrosylation.
authors.affiliation: Department of Pharmacology and Physiology, New Jersey Medical School, University of Medicine and Dentistry of New Jersey, Newark, NJ 07101, USA.
authors.forename: Nazish
authors.initials: N
authors.lastname: Sayed
authors.forename: David D
authors.initials: DD
authors.lastname: Kim
authors.forename: Xavier
authors.initials: X
authors.lastname: Fioramonti
authors.forename: Toru
authors.initials: T
authors.lastname: Iwahashi
authors.forename: Walter N
authors.initials: WN
authors.lastname: Durán
authors.forename: Annie
authors.initials: A
authors.lastname: Beuve
mesh_terms: D000818:Animals; D001160:Arterioles / Q000187:drug effects / Q000502:physiology; D006224:Cricetinae; D003545:Cysteine / Q000031:analogs & derivatives / Q000494:pharmacology; D004361:Drug Tolerance / Q000502:physiology*; D004789:Enzyme Activation / Q000187:drug effects / Q000502:physiology; D006162:Guanylate Cyclase / Q000235:genetics / Q000378:metabolism*; D009061:Mouth Mucosa / Q000098:blood supply / Q000187:drug effects / Q000201:enzymology; D009566:Nitrates / Q000378:metabolism* / Q000502:physiology; D005996:Nitroglycerin / Q000494:pharmacology*; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics / Q000378:metabolism*; D026403:S-Nitrosothiols / Q000494:pharmacology; D000071756:Soluble Guanylyl Cyclase; D014664:Vasodilation / Q000187:drug effects* / Q000502:physiology*
chemical_list: D009566:Nitrates; D018160:Receptors, Cytoplasmic and Nuclear; D026403:S-Nitrosothiols; C021315:S-nitrosocysteine; D006162:Guanylate Cyclase; D000071756:Soluble Guanylyl Cyclase; D005996:Nitroglycerin; D003545:Cysteine