Effect of one-kidney, one clip hypertension on the structure and function of porcine intramyocardial small arteries

Bund, Stuart J.; Oldham, Alex A.; Allott, Christopher P.; Loveday, Bernard E.; Heagerty, Anthony M.

doi:10.1097/00004872-199505000-00009

Cited by 7 publications

(7 citation statements)

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“…Such structural modifications are also observed in coronary arteries from the SHR [27][28][29] and in hypertensive pigs [30], The wall thickening observed in this study was not associated with greater myogenic tone in intact SHR arteries except at the highest pressures. Similar observations have been made in adult SHR small mesenteric arteries [5], However, the ability of SHR arteries to withstand forced dilatation at the higher pressures may be a consequence of the ob served structural differences.…”

Section: Discussionsupporting

confidence: 71%

Myogenic Tone in Coronary Arteries from Spontaneously Hypertensive Rats

García

Izzard²,

Heagerty³

et al. 1997

J Vasc Res

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The aims of this study were to investigate myogenic tone in cannulated coronary arteries from SHR (spontaneously hypertensive rats) and WKY (Wistar-Kyoto rats) at 5 and 20 weeks of age under pressurised no-flow conditions. Pressure-diameter relationships (20-200 mm Hg) were determined in the presence (active) and absence (passive) of calcium and myogenic tone at each pressure was calculated. Active, but not passive diameter-pressure relationships were significantly different between strains at both ages. Active diameters were similar between strains at pressures up to 140 mm Hg at 5 and 20 weeks. At higher pressures SHR arteries generated more tone. Maximum myogenic tone was similar between strains in spite of increased wall thickness in the SHR at both ages. Endothelium denudation increased myogenic tone to a greater extent in the SHR at both ages. Active diameters of endothelium-denuded SHR arteries were smaller than those of WKY in the range 20-120 mm Hg at 5 week and 20-80 and 160-180 mm Hg at 20 weeks. These results demonstrate that during both the developmental and established phases of hypertension, myogenic tone is not enhanced in intact SHR coronary arteries, except at the highest pressures. Following endothelium removal SHR arteries generated greater myogenic tone also at lower pressures. These data demonstrate a greater endothelium-mediated antagonism of myogenic tone in SHR coronary arteries.

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Section: Discussionsupporting

confidence: 71%

Myogenic Tone in Coronary Arteries from Spontaneously Hypertensive Rats

García

Izzard²,

Heagerty³

et al. 1997

J Vasc Res

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“…The calculated remodelling and growth indices [4] were 93% and 18%, respectively. Therefore the arteries used in this study were characterised by similar differ ences between the two groups as reported previously [6]. Cm|n did not differ significantly, but at Co and Cioo arter ies from hypertensive pigs were under less strain (table 3).…”

Section: Resultssupporting

confidence: 65%

“…The procedures employed to induce one-kidney, one-clip hyper tension and for blood pressure determination in miniature pigs have been described in detail together with those for the determination o f coronary artery structure in these arteries using the small vessel myo graph technique [6], The pigs used for this study were those utilised previously [6] except for the loss o f 4 normotensive controls (since length-tension data were no longer available) and with the addition of 6 further surgically modified animals.…”

Section: Methodsmentioning

confidence: 99%

“…However, it has been demonstrated that a reduced distensibility can also account for reduced lumen diameters in hypertension [5], Previously, we have reported an increased media thickness and reduced lu men diameter of small coronary arteries from pigs with one-kidney, one-clip hypertension and ascribed these ar chitectural modifications to a remodelling process since no significant hypertrophy occurred (i.e. no significant increase in media cross-sectional area) [6], However, giv-en that an increased wall stiffness might also be a causa tive possibility, it was decided to perform a retrospective study to determine whether distensibility was indeed altered in these arteries. Since the methods employed for the measurement of vascular structure were based on determinations of length-tension relationships and wall geometry measurements a more thorough investigation of arterial mechanics was possible.…”

Section: Introductionmentioning

confidence: 92%

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Mechanical Properties of Porcine Small Coronary Arteries in One-Kidney, One-Clip Hypertension

Bund

Oldham²,

Heagerty³

1996

J Vasc Res

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The purpose of this study was to analyse the mechanical properties of small coronary arteries from pigs with one-kidney, one-clip hypertension and normotensive control animals and to determine whether these could contribute to vascular structural changes observed in hypertension. Small coronary artery wall tension-internal circumference relationships were determined for coronary arteries mounted in a myograph and used to calculate incremental elastic modulus-stress relationships for arteries from normotensive and hypertensive pigs. Wall tension-internal circumference relationships were shifted to the left in arteries from hypertensive pigs, but the stress-strain and incremental elastic modulus-stress relationships were not influenced by the increased blood pressure load. These data indicate that small coronary arteries from hypertensive pigs are not less distensible than those from normotensive controls. Therefore the previously reported increased media thickness:lumen diameter ratios in coronary arteries in this model of hypertension are not a consequence of abnormal elastic properties and can be ascribed to a remodelling process.

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“…22 In guinea pigs, however, no attenuation of the vasodilatory effect of substance P was demonstrated. 23 Circulating levels of substance P in human hypertension are unaltered, 10,24 decreased 25,26 or increased. 27,28 Furthermore, medication (prazosin, captopril) may increase circulating levels of substance P in human hypertension.…”

Section: Journal Of Human Hypertensionmentioning

confidence: 99%

Enhanced vasodilator responses to calcitonin gene-related peptide (CGRP) in subcutaneous arteries in human hypertension

Lind

Edvinsson

2002

J Hum Hypertens

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Isolated segments (1-2 mm) of small subcutaneous arteries (diameter 0.1-0.9 mm) and veins (0.1-1.0 mm) from patients with hypertension (essential n ‫؍‬ 13, renovascular n ‫؍‬ 6) and controls (n ‫؍‬ 17) were examined. The relaxant responses to the sensory transmitters calcitonin gene-related peptide (CGRP) and substance P, and the contractile responses to potassium and noradrenaline were studied. Enhanced dilatory responses (E max ) but no change in sensitivity (pEC 50 ) were demonstrated in the arteries but not in the veins to CGRP in hypertensives (P Ͻ 0.01) as compared with normotensives, and in the hypertensive subgroups (essential hypertension, P Ͻ 0.05; renovascular hypertension, P Ͻ 0.05). The relaxant responses to substance P were not

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Effect of one-kidney, one clip hypertension on the structure and function of porcine intramyocardial small arteries

Cited by 7 publications

References 0 publications

Myogenic Tone in Coronary Arteries from Spontaneously Hypertensive Rats

Myogenic Tone in Coronary Arteries from Spontaneously Hypertensive Rats

Mechanical Properties of Porcine Small Coronary Arteries in One-Kidney, One-Clip Hypertension

Enhanced vasodilator responses to calcitonin gene-related peptide (CGRP) in subcutaneous arteries in human hypertension

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