S-nitrosocysteine elicits hemodynamic responses similar to those of the Bezold-Jarisch reflex via activation of stereoselective recognition sites.
We report here that L-S-nitrosocysteine elicits rapid dose-dependent reductions in mean arterial blood pressure, heart rate, cardiac output and renal sympathetic nerve activity in conscious rats whereas D-S-nitrosocysteine elicits minor responses. The reductions in mean arterial blood pressure, heart rate and cardiac output elicited by L- and D-S-nitrosocysteine were markedly diminished after blockade of cardiac muscarinic cholinergic receptors whereas the reductions in renal sympathetic nerve activity were not affected. The Bezold-Jarisch reflex-like pattern of responses elicited by the stereoisomers, suggests that (i) L- and L-S-nitrosocysteine may activate stereoselective recognition sites on vagal cardiopulmonary afferents, which elicit hemodynamic responses via increases in cardiovagal efferent nerve activity and decreases in sympathetic nerve activity, and (ii) L-S-nitrosocysteine is a more potent agonist of these recognition sites than is D-S-nitrosocysteine.
Lewis
Stephen J
SJ
Department of Pharmacology and Physiology, University of Georgia, Athens, Georgia 30602-7389, USA. slewis@vet.uga.edu
Owen
Joy R
JR
Bates
James N
JN
D000818:Animals; D001665:Binding Sites; D001794:Blood Pressure / Q000187:drug effects*; D002302:Cardiac Output / Q000187:drug effects; D003243:Consciousness; D003545:Cysteine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology; D003553:Cystine / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D006339:Heart Rate / Q000187:drug effects*; D007668:Kidney / Q000294:innervation; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012018:Reflex / Q000187:drug effects; D026403:S-Nitrosothiols / Q000737:chemistry / Q000494:pharmacology*; D013237:Stereoisomerism; D013564:Sympathetic Nervous System / Q000187:drug effects; D014665:Vasodilator Agents / Q000737:chemistry / Q000494:pharmacology
D026403:S-Nitrosothiols; D014665:Vasodilator Agents; D003553:Cystine; C021315:S-nitrosocysteine; D003545:Cysteine