Guanylate cyclase and not ATP-dependent K+ channels seems temperature-dependent in smooth muscle relaxation of human umbilical arteries

Tiritilli, A.

doi:10.1016/s0014-2999(00)00529-x

Cited by 5 publications

(11 citation statements)

References 19 publications

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“…With our data we cannot suggest which mechanisms underlie the decreased sensitivity to diazoxide, isoproterenol and magnesium sulphate during cooling. Our results are in agreement with those reported by Tiritilli 3) who has reported that cooling decreased nicorandil, a ATPsensitive K ＋ channel-opener, induced relaxation in umbilical arteries. No previous data on the eŠects of diazoxide, isoproterenol and magnesium sulphate of human umbilical artery during cooling have been published.…”

Section: Discussionsupporting

confidence: 94%

“…With our data we cannot suggest which mechanisms underlie this decreased sensitivity during cooling. Our results are in agreement with those reported by Tritilli, 3) who has shown that cooling decreases nicorandil relaxation in umbilical arteries and nitric oxide pathway appears relatively unimportant, as pretreatment with L-arginine or the inhibition of nitric oxide-synthase by L-NNA did not modify the relaxation response to nicorandil. Furthermore, Bodellson et al 31) reported that cooling speciˆcally alters the sensitivity to various drugs in diŠerent parts of the vascular systems; in the rat jugular vein, cooling markedly augments the contraction to 5-HT and it has been found that this augmentation is dependent of an intact endothelium.…”

Section: Discussionsupporting

confidence: 93%

“…1) Lowering the temperature (cooling) has been shown to have a variable in‰uence on vascular sensitivity to various drugs and endogenous substances in diŠerent parts of the vascular system of animals. 2,3) Most of the previous studies examining the eŠect of cooling on smooth muscle responses have focused on the eŠects of contractile agents and information about vasodilators is rather limited. Saito et al 4) reported that in guineapig myocardium and aorta the vasorelaxant eŠects of K ＋ channel openers, NIP-121, cromakalim, and pinacidil, were greatly reduced during cooling.…”

Section: Introductionmentioning

confidence: 99%

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Role of the Nitric Oxide on Relaxation of the Human Umbilical Artery during Cooling

2011

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In the present study, the eŠects of cooling (to 28°C) on the vasodilatation induced by diazoxide (10 -9 -3×10 -4 M), isoproterenol (10 -9 -3×10 -4 M) and magnesium sulphate (0.1 30 mM) on serotonin-pre-contracted human umbilical artery and the role of nitric oxide in these eŠects were analyzed. Diazoxide, isoproterenol and magnesium produced concentration-dependent relaxation of human umbilical artery precontracted with serotonin (10 -6 M). During cooling, the pIC 50 values and maximal responses to these agents were signiˆcantly lower than at 37°C. Cooling to 28°C in the presence of N G -nitro-L-arginine methyl ester (L-NAME, 10 -4 M) did not modify the eŠects of temperature on diazoxide, isoproterenol and magnesium-induced relaxations. These results suggest that cooling-induced changes of diazoxide, isoproterenol, and magnesium sulphate in human umbilical artery are independent of nitric oxide.

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Section: Discussionsupporting

confidence: 94%

Section: Discussionsupporting

confidence: 93%

Section: Introductionmentioning

confidence: 99%

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Role of the Nitric Oxide on Relaxation of the Human Umbilical Artery during Cooling

2011

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“…Previously, Cogolludo et al 28 suggested that in rat aorta, the contribution of the K ATP channel opening to the vasorelaxation is more important at high concentrations of nicorandil. Also, this result is in agreement with those in human umbilical arteries 29 and rabbit femoral artery, 30 which demonstrates that glibenclamide partially antagonized the relaxation induced by nicorandil. Effects of K + channel blockers on the nicorandil-induced relaxation of HSV precontracted by phenylephrine (10 mM).…”

Section: Discussionsupporting

confidence: 88%

Different K+ Channels Are Involved in Relaxation of Arterial and Venous Graft Induced by Nicorandil

Novakovic

Pavlović

Stojanović

et al. 2011

Journal of Cardiovascular Pharmacology

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The drug nicorandil is a vasodilator approved for the treatment of angina. In addition to its well-known effect on the opening of ATP-sensitive K (KATP) channels, nicorandil-induced vasorelaxation also involves the opening of Ca-activated K channels. The aim of this study was to investigate the effects of nicorandil on the isolated human internal mammary artery (HIMA) and the human saphenous vein (HSV) and to define the contribution of different K channel subtypes in the nicorandil action on these arterial and venous grafts. Our results show that nicorandil induced a concentration-dependent relaxation of HSV and HIMA rings precontracted by phenylephrine. Glibenclamide, a selective KATP channels inhibitor, partially inhibited the response to nicorandil in both HSV and HIMA. Iberiotoxin, a most selective blocker of large-conductance Ca-activated K (BKCa) channels, partly antagonized relaxation of HIMA. A nonselective blocker of voltage-gated K channels, 4-aminopyridine caused partial inhibition of the nicorandil-induced relaxation of HSV but did not antagonize relaxation of HIMA induced by nicorandil. Margatoxin, a potent inhibitor of KV1.3 channels, did not abolish the effect of nicorandil on HSV and HIMA. Our results showed that nicorandil induced strong endothelium-independent relaxation of HSV and HIMA contracted by phenylephrine. It seems that KATP and 4-aminopyridine-sensitive K channels located in the smooth muscle of HSV mediated relaxation induced by nicorandil. In addition, KATP and BKCa channels are probably involved in the nicorandil action on HIMA.

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“…The human umbilical artery and vein are easily accesible human smooth muscle preparations used frequently for functional studies but there is limited information [23,24] about the effect of temperature on the contractile responses of umbilical vessels. The human umbilical artery and vein are easily accesible human smooth muscle preparations used frequently for functional studies but there is limited information [23,24] about the effect of temperature on the contractile responses of umbilical vessels.…”

Section: Discussionmentioning

confidence: 99%

Effects of cooling and warming on 5‐hydroxytryptamine‐ and acetylcholine‐induced contractions of human umbilical vessels: role of nitric oxide

Atalık¹,

Kılıç²,

Nurullahoğlu³

et al. 2008

Fundamemntal Clinical Pharma

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The effects of cooling (to 28 degrees C) and warming (to 41 degrees C) on the vasoconstrictions induced by 5-hydroxytryptamine (5-HT) and acetylcholine (ACh) and the role of nitric oxide in these effects were analyzed in human umbilical artery and vein. 5-HT (10(-9)-10(-4) M) and ACh (10(-9)-10(-4) M) induced concentration-dependent contractions at 37, 28 and 41 degrees C. During cooling, the sensitivity, but not the maximal response, of 5-HT and ACh was significantly higher than at 37 degrees C; and during warming, again the sensitivity, but not the maximal response, of both contractile agents was significantly lower than at 37 degrees C. Neither cooling to 28 degrees C nor warming to 41 degrees C, after treatment with N(G)-nitro-L-arginine methyl esther (L-NAME, 10(-4) M), modify the effect of temperature in both vessels. These results suggest that cooling- and warming-induced responses in human umbilical artery and vein are independent of nitric oxide.

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Guanylate cyclase and not ATP-dependent K+ channels seems temperature-dependent in smooth muscle relaxation of human umbilical arteries

Cited by 5 publications

References 19 publications

Role of the Nitric Oxide on Relaxation of the Human Umbilical Artery during Cooling

Role of the Nitric Oxide on Relaxation of the Human Umbilical Artery during Cooling

Different K+ Channels Are Involved in Relaxation of Arterial and Venous Graft Induced by Nicorandil

Effects of cooling and warming on 5‐hydroxytryptamine‐ and acetylcholine‐induced contractions of human umbilical vessels: role of nitric oxide

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