Actions of S-nitrosocysteine in the nucleus tractus solitarii are unrelated to release of nitric oxide

Brain Res. 1997 Jan 23;746(1-2):98-104. doi: 10.1016/s0006-8993(96)01188-2.


Cardiovascular effects elicited by microinjection of L-S-nitrosocysteine in the nucleus tractus solitarii (NTS) were compared and contrasted with those produced by the dextroisomer, other nitric oxide donors and nitric oxide itself. L-S-nitrosocysteine produced dose-related decreases of arterial pressure and heart rate. In contrast, D-S-nitrosocysteine, S-nitrosoglutathione, glyceryl trinitrate, and sodium nitroprusside produced minimal responses that were not dose-related. Likewise, injection of cystine and nitric oxide, two products of S-nitrosocysteine breakdown, produced no significant response. Headspace analysis using chemiluminescence revealed that L- and D-S-nitrosocysteine released identical amounts of nitric oxide when exposed to homogenates of whole rat brain. Responses to L-S-nitrosocysteine were not affected by local injection of oxyhemoglobin or the nitric oxide synthase inhibitor L-nitroarginine methylester. Although injection of L-cysteine into the NTS produced responses similar to those seen with injection of L-S-nitrosocysteine, blockade of excitatory amino acid receptors with kynurenic acid inhibited responses to cysteine but not those to the nitrosothiol. The study demonstrates that S-nitrosocysteine is biologically active in the NTS. Its action is independent of release of nitric oxide from the nitrosothiol but may be mediated through stereoselective sites on target neurons.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Blood Pressure / drug effects
  • Cysteine / analogs & derivatives*
  • Cysteine / pharmacology
  • Dose-Response Relationship, Drug
  • Enzyme Inhibitors / pharmacology
  • Excitatory Amino Acid Antagonists / pharmacology
  • Heart Rate / drug effects
  • Kynurenic Acid / pharmacology
  • Luminescent Measurements
  • Male
  • Microinjections
  • NG-Nitroarginine Methyl Ester / pharmacology
  • Neurons, Afferent / drug effects
  • Neurons, Afferent / metabolism
  • Nitric Oxide / metabolism*
  • Nitroprusside / pharmacology
  • Oxyhemoglobins / pharmacology
  • Rats
  • Rats, Sprague-Dawley
  • S-Nitrosothiols*
  • Signal Transduction / drug effects
  • Solitary Nucleus / cytology
  • Solitary Nucleus / drug effects*
  • Solitary Nucleus / metabolism
  • Vasodilator Agents / pharmacology


  • Enzyme Inhibitors
  • Excitatory Amino Acid Antagonists
  • Oxyhemoglobins
  • S-Nitrosothiols
  • Vasodilator Agents
  • Nitroprusside
  • Nitric Oxide
  • S-nitrosocysteine
  • Kynurenic Acid
  • Cysteine
  • NG-Nitroarginine Methyl Ester