RRC ID 108
著者 Ozawa Y, Hayashi K, Kanda T, Homma K, Takamatsu I, Tatematsu S, Yoshioka K, Kumagai H, Wakino S, Saruta T.
タイトル Impaired nitric oxide- and endothelium-derived hyperpolarizing factor-dependent dilation of renal afferent arteriole in Dahl salt-sensitive rats.
ジャーナル Nephrology (Carlton)
Abstract BACKGROUND AND AIMS:We previously demonstrated that acetylcholine elicited nitric oxide-dependent sustained and endothelium-derived hyperpolarizing factor (EDHF)-dependent transient dilation of afferent arterioles. The present study examined whether free radicals interacted with nitric oxide-dependent and EDHF-dependent vasodilator mechanisms in renal microvessels of salt-sensitive hypertension, using the isolated perfused hydronephrotic kidney.
METHODS AND RESULTS:Following the pretreatment with indomethacin (100 micromol/L) with or without nitro- l-arginine methylester (100 micromol/L), the effect of acetylcholine on noradrenaline (0.3 micromol/L)-induced constriction was evaluated in kidneys from Dahl salt-sensitive and salt-resistant rats. Although acetylcholine (0.01-10 micromol/L) caused dose-dependent and sustained vasodilation of afferent arterioles, attenuated dilation was observed in Dahl salt-sensitive rats, compared with that in salt-resistant rats (58 +/- 4 vs 101 +/- 11% reversal at 10 micromol/L acetylcholine). In the presence of nitro- l-arginine methylester, acetylcholine elicited only transient dilation, with vasodilator response blunted in Dahl salt-sensitive rats (64 +/- 4 vs 100 +/- 9% reversal at 10 micromol/L acetylcholine). Furthermore, chronic (8-10 weeks) treatment with tempol caused partial restoration of acetylcholine (10 micromol/L)-induced sustained arteriolar dilation (71 +/- 3% reversal), but complete reversal of transient dilation (92 +/- 4% reversal). Finally, acute treatment with tempol not only improved the sustained component of the acetylcholine-induced dilation but also restored the impaired responsiveness of transient dilation in Dahl salt-sensitive rats.
CONCLUSION:Both sustained (nitric oxide-mediated) and transient (EDHF-mediated) components of acetylcholine-induced afferent arteriolar dilation were attenuated in Dahl salt-sensitive rats, which was attributed, in part, to enhanced free radical activity. A reversal of the sustained and transient vasodilation by the acute tempol treatment suggests possible interaction between free radicals and EDHF as well as increased bioavailability of nitric oxide.
巻・号 9(5)
ページ 272-7
公開日 2004-10-1
DOI 10.1111/j.1440-1797.2004.00292.x
PII NEP292
PMID 15504139
MeSH Acetylcholine / pharmacology Animals Arterioles / physiopathology Biological Factors / physiology* Endothelium, Vascular / physiopathology* Hypertension / physiopathology* Kidney / blood supply* Kidney / physiopathology* Male Nitric Oxide / physiology* Rats Rats, Inbred Dahl Vasodilation / drug effects
IF 1.749
引用数 15
WOS 分野 UROLOGY & NEPHROLOGY
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