In vivo evidence that L-S-nitrosocysteine may exert its vasodilator effects by interaction with thiol residues in the vasculature.
This study examined the effects of the lipophobic thiol chelator, para-hydroxymercurobenzoic acid (25 and 50 micromol/kg, i.v.) on the falls in mean arterial blood pressure and regional vascular resistances produced by L-S-nitrosocysteine (400 nmol/kg, i.v.) and the nitric oxide (NO)-donors, (Z)-1-&z. sfnc;N-methyl-N-[6(N-methylammoniohexyl)amino]&z.sfnc; diazen-1-ium-1, 2-diolate (MAHMA NONOate, 25 nmol/kg, i.v.) and sodium nitroprusside (10 microg/kg, i.v.), in urethane-anesthetized rats. The L-S-nitrosocysteine-induced responses were markedly diminished whereas the MAHMA NONOate- and sodium nitroprusside-induced responses were minimally affected by para-hydroxymercurobenzoic acid. These results suggest that the vasodilator actions of L-S-nitrosocysteine involves the interaction with membrane thiols in vascular smooth muscle of resistance arteries and that para-hydroxymercurobenzoic acid does not markedly affect NO-mediated vasodilation.
Hoque
A
A
The Department of Pharmacology, University of Iowa, IA 52242, USA.
Bates
J N
JN
Lewis
S J
SJ
D000818:Animals; D001808:Blood Vessels / Q000187:drug effects* / Q000502:physiology; D003545:Cysteine / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology; D006439:Hemodynamics / Q000187:drug effects; D006834:Hydrazines / Q000494:pharmacology; D006902:Hydroxymercuribenzoates / Q000494:pharmacology; D008297:Male; D009599:Nitroprusside / Q000494:pharmacology; D009603:Nitroso Compounds / Q000378:metabolism / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D026403:S-Nitrosothiols; D013438:Sulfhydryl Compounds / Q000378:metabolism*; D014664:Vasodilation / Q000187:drug effects*; D014665:Vasodilator Agents / Q000378:metabolism / Q000494:pharmacology
C105785:1-hexanamine-6-(2-hydroxy-1-methyl-2-nitrosohydrazine)-N-methyl; D006834:Hydrazines; D006902:Hydroxymercuribenzoates; D009603:Nitroso Compounds; D026403:S-Nitrosothiols; D013438:Sulfhydryl Compounds; D014665:Vasodilator Agents; C030601:4-hydroxymercuribenzoate; D009599:Nitroprusside; C021315:S-nitrosocysteine; D003545:Cysteine