Predominant α1Adrenoceptor-Mediated Contraction in the Human Internal Mammary Artery

He, Guo Wei; Shaw, John H.; Hughes, Clifford F.; Yang, Cheng; Thomson, Duncan; McCaughan, Brian C.; Hendle, P. N.; Baird, D. K.

doi:10.1097/00005344-199302000-00011

Cited by 55 publications

(46 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In the present study, although ET-1 induced a strong contraction (5.57 ± 0.93 g) in the human IMA, and in some ET-1-contracted rings, which were attempted to reverse the contraction by washout, even frequent washing hardly reduced the tone to the baseline, the contraction force automatically reduced with the time (Figures 2 and 3). In contrast, we have previously observed that TxA2 [7], a-adrenoceptor agonists [19][20][21], and potassium [7] may induce a sustained contraction in this artery. In comparison with the findings in other vessels [58], our findings may suggest that the stability of ET-1-induced contraction is vessel-selective.…”

Section: Discussionmentioning

confidence: 69%

“…Human IMA [18,19]. Briefly, the rings were stretched-up in progressive steps to determine the length-tension exponential curve for each ring.…”

Section: Generalmentioning

confidence: 99%

“…This concentration of ET-1 was the submaximal concentration which was determined from the logistic-curve fitting equation [18,19] from pilot experiments. Cumulative concentration-relaxation curves to GTN (n = 7) were then established.…”

Section: Generalmentioning

confidence: 99%

See 2 more Smart Citations

Interaction between endothelin and vasodilators in the human internal mammary artery.

He¹,

Yang²,

Mack³

et al. 1994

Brit J Clinical Pharma

View full text Add to dashboard Cite

1. The internal mammary artery (IMA) is the primary choice as an arterial graft for coronary artery bypass surgery. Endothelin (ET) has been recently measured with an increased release after cardiopulmonary bypass for coronary artery bypass grafting. Threshold concentrations of ET‐1 have been found to amplify specifically contractions induced by noradrenaline and serotonin. This study was designed to investigate the effect of glyceryl trinitrate (GTN) and calcium antagonists on ET‐1 contraction in the human IMA. 2. Human IMA segments taken from 21 patients undergoing IMA‐coronary artery bypass grafting were mounted in an organ bath under the physiological pressure determined from their own length‐tension curves. Four ring segments were allocated into four groups. One served as a control and the others were treated with GTN (10, 100 nM, or 30 microM) for 5 min or nifedipine (20 or 200 nM, or 30 microM) for 25 min before concentration‐contraction curves to ET‐1 were established. In separate experiments, the concentration‐relaxation curves to GTN or nifedipine were established in the IMA rings precontracted with ET‐1 (10 nM). 3. Pretreatment of IMA with GTN for 5 min did not alter the ET‐1‐induced contraction. Pretreatment with 20 or 200 nM of nifedipine slightly but not significantly, altered the maximum contraction induced by ET‐1. Higher concentrations (30 microM) significantly reduced the maximum contraction force (P = 0.008). On the other hand, GTN caused 76.44 +/‐ 6.35% relaxation in ET‐1‐precontracted IMA. In contrast, the nifedipine‐induced relaxation was difficult to establish due to unsustained contraction to ET‐1.(ABSTRACT TRUNCATED AT 250 WORDS)

show abstract

Section: Discussionmentioning

confidence: 69%

“…Human IMA [18,19]. Briefly, the rings were stretched-up in progressive steps to determine the length-tension exponential curve for each ring.…”

Section: Generalmentioning

confidence: 99%

See 1 more Smart Citation

Interaction between endothelin and vasodilators in the human internal mammary artery.

He¹,

Yang²,

Mack³

et al. 1994

Brit J Clinical Pharma

View full text Add to dashboard Cite

show abstract

“…Any discarded distal IMA segments were collected and placed in a container with oxygenated, physiological solution (Krebs') maintained at 4"C, and then transferred to the laboratory. The details of collecting, dissecting, and mounting of the IMA rings and the organ bath technique have been described previously [14][15][16][17][18][19]. Briefly, the rings were stretched-up in progressive steps to determine the length-tension curve for each ring.…”

Section: Methodsmentioning

confidence: 99%

Potential greater than additive vasorelaxant actions of milrinone and nitroglycerin on human conduit arteries

Yang

Gately

et al. 1996

Brit J Clinical Pharma

Self Cite

View full text Add to dashboard Cite

1 The mechanism of vasorelaxation for phosphodiesterase I11 inhibitors is mediated by increase of cAMP whereas for nitrovasodilators, cGMP. Pretreatment with the combination depressed contraction to a higher extend compared with milrinone alone (P < 0.05) for the K+-induced contraction and to NTG alone ( P < 0.05) in U46619-induced contraction. Treatment with the combination also shifted ECS0 rightward and this shift was significantly more than that caused by treatment with NTG alone (P

show abstract

“…[30,31,35] But He et al [35] have found that methoxamine (MO) and norepinephrine (NE) causes vasoconstriction on ITA, and the contractions induced by both MO and NE were totally abolished by 1 -antagonist prazosin but not 2 -antagonist yohimbine. As a result, they offered that in the human ITA the postjunctional -adrenoceptors are predominantly of the 1 -subtype.…”

Section: Discussionmentioning

confidence: 99%

In Vitro Effects Of Dopamine On Internal Thoracic Artery Graft Which Is Used In Coronary Artery Bypasses

Halıcı¹,

Ege²,

Karadağ³

et al. 2009

TUTFD

View full text Add to dashboard Cite

© Trakya Üniversitesi T p Fakültesi Dergisi. AVES Yay nc l k taraf ndan bas lm t r. Her hakk sakl d r. © Medical Journal of Trakya University. Published by AVES Publishing. All rights reserved. In Vitro Effects of Dopamine on Internal Thoracic Artery Graft Used inM-10 -7 M produced a mild relaxant effect on phenylephrine-precontracted ITA, and at higher concentrations than 10 -7 M it produced a constrictor response. Ther relaxant effect of dopamine was partially antagonized by L-NAME (nitric oxide synthase inhibitor, 10 -6 M), propranolol (10 -6 M), and cis--flupenthixol (dopaminergic receptor antagonist, 10 -6 M), but not by metoclopramide (D 2 -dopaminergic receptor antagonist). The constrictor effect of dopamine was partially antagonized by phentolamine, prazosin and, yohimbine. Conclusion:It was concluded that, while dopamine produces a vasodilator response at the lower concentrations, it causes a constrictor effect on ITA at the higher concentrations. Both a -adrenergic and a nitric oxide mediated mechanism (via D 1 -dopaminergic receptor) may play a role in the relaxant effect of dopamine on ITA at the lower concentrations. Constrictor response to dopamine at the higher concentrations on ITA may be produced by the activation of 1 -and 2 -adrenergic receptors.Key words: Internal thoracic artery; coronary artery bypass surgery; dopamine. Amaç:Bu çal man n amac dopaminin internal torasik arter ( TA) grefti üzerine etkilerini, invitro ara t rmakt r. Gereç ve Yöntemler: Aral k 2003-Haziran 2005 tarihleri aras nda klini imizde koroner arter bypass greft (CABG)operasyonu olan toplam 32 hasta (2'si kad n 30'u erkek, ortalama ya ; 59.256±8,.34, 37-75 ya lar aras ) çal maya al nd . n vitro organ banyosunda hastalar n ITA'lar ndan arta kalan parçac klar üzerinde dopaminin olu turdu u kas c ve gev etici yan tlar isometrik olarak kaydedildi. Bulgular: Dopamin 10-9 M-10 -7 M konsantrasyon aral nda fenilefrinle önceden kast r lm ITA'da hafif bir gev eme yan t , sonras nda artan konsantrasyonlar nda (>10 -7 M) kas lma yan t gerçekle tirdi i gözlendi. Dopaminin gev etici etkisinin k smen L-NAME (nitrik oksit sentaz inhibitorü, 10 -6 M), propranolol (10 -6 M) ve cis--flupentiksol (dopaminerjik reseptör antagonisti, 10 -6 M) ile k smen azald fakat metoklopramidin (D 2 -dopaminerjik reseptör antagonisti) dopaminin kaynakl gev emeye etki yapmad gözlendi. Dopaminin ITA'daki kas c etkisi k smen fentolamin, prazosin ve yohimbin ile antagonize edildi i gözlendi.Sonuç: Sonuç olarak dopamin dü ük konsantrasyonlarda ITA'da vazodilatasyon yan t n olu tururken daha yüksek konsantrasyonlarda ITA'da vasokonstriksiyon yan t n olu turmaktad r. -adrenerjik ve nitrik oksit arac l mekanizma (D 1 -dopaminerjik reseptör yoluyla) dopaminin dü ük konsantrasyonlar nda ITA'da olu turdu u gev etici etkide rol alabilir. Dopaminin yüksek konsantrasyonlardaki ITA'da olu turdu u kas c etki 1 -ve 2 -adrenerjik reseptörlerin aktivasyonu ile olu turulmaktad r.Anahtar sözcükler: nternal torasik arter; koroner arter bypass cerrahisi; dopamin Trakya Univ Tip ...

show abstract

Predominant α1Adrenoceptor-Mediated Contraction in the Human Internal Mammary Artery

Cited by 55 publications

References 0 publications

Interaction between endothelin and vasodilators in the human internal mammary artery.

Interaction between endothelin and vasodilators in the human internal mammary artery.

Potential greater than additive vasorelaxant actions of milrinone and nitroglycerin on human conduit arteries

In Vitro Effects Of Dopamine On Internal Thoracic Artery Graft Which Is Used In Coronary Artery Bypasses

Contact Info

Product

Resources

About