Different responses of mesenteric artery from normotensive and spontaneously hypertensive rats to nitric oxide and its redox congeners.
The conversion of nitric oxide (NO*) into its congeners nitrosonium (NO(+)) and nitroxyl (HNO/NO(-)) ions may have important consequences for signal transduction and physiological responses. Manganese-containing superoxide dismutase (MnSOD) may convert NO. into its redox congeners. In our current work, we have examined the mechanism of sodium nitroprusside (SNP)-induced relaxation of arteries, with or without endothelium, from both normotensive and spontaneously hypertensive (SH) rats in the absence and presence of MnSOD. SNP induced a greater degree of relaxation in normotensive than in SH rats. MnSOD antagonized SNP-induced relaxation and effect was greater in normotensive than hypertensive rats. However, MnSOD even potentiated SNP-induced relaxation in mesenteric arteries with endothelium from SH rats. Our results indicate that HNO/NO(-)-mediated relaxation is more effective in mesenteric artery smooth muscle from SH rats than from normotensive rats and that vascular dysfunction in SH rats is not solely endothelium-derived but involves changes in vascular smooth muscles.
Orescanin
Zorana S
ZS
Department of Physiology, Institute for Biological Research Sinisa Stanković, Bulevar Despota Stefana 142, 11060 Belgrade, Serbia.
Milovanović
Slobodan R
SR
Spasić
Snezana D
SD
Jones
David R
DR
Spasić
Mihajlo B
MB
D000818:Animals; D006973:Hypertension / Q000503:physiopathology*; D066298:In Vitro Techniques; D008297:Male; D008638:Mesenteric Arteries / Q000187:drug effects* / Q000502:physiology; D009569:Nitric Oxide / Q000378:metabolism; D020030:Nitric Oxide Donors / Q000494:pharmacology*; D009599:Nitroprusside / Q000494:pharmacology*; D051381:Rats; D011918:Rats, Inbred SHR; D017208:Rats, Wistar; D013482:Superoxide Dismutase / Q000494:pharmacology; D014664:Vasodilation / Q000187:drug effects
D020030:Nitric Oxide Donors; D009599:Nitroprusside; D009569:Nitric Oxide; D013482:Superoxide Dismutase