Stereoselective S-nitrosocysteine recognition sites in rat brain.
We examined the effects of intracisternal (i.c.) injections (10-250 nmol) of the L- and D-isomers of S-nitrosocysteine (L- and D-S-nitrosocysteine) on the mean arterial blood pressure and heart rate of conscious rats, and the decomposition of L- and D-S-nitrosocysteine to nitric oxide (NO) upon addition to brain homogenates. The i.c. injection of L-S-nitrosocysteine produced initial falls in mean arterial blood pressure and heart rate which were followed by increases in these parameters. The i.c. injection of D-S-nitrosocysteine did not produce initial falls in mean arterial blood pressure or heart rate but produced the subsequent increases in these parameters. L- and D-S-nitrosocysteine decomposed equally to NO. These results suggest that the initial effects of L-S-nitrosocysteine may be due to the activation of stereoselective recognition sites on brain neurons.
Lewis
S J
SJ
Department of Pharmacology, University of Iowa, Iowa City 52242, USA.
Travis
M D
MD
Bates
J N
JN
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D001921:Brain / Q000378:metabolism*; D003545:Cysteine / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology; D006339:Heart Rate / Q000187:drug effects; D007536:Isomerism; D051381:Rats; D017207:Rats, Sprague-Dawley; D026403:S-Nitrosothiols
D026403:S-Nitrosothiols; C021315:S-nitrosocysteine; D003545:Cysteine