Unidirectional rate sensitivity component in local control of vascular tone

Smiesko, V

doi:10.1007/bf00588451

Cited by 23 publications

(9 citation statements)

References 21 publications

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“…This diameter increase occurred immediately on release of the occlusion and persisted for less than 10 seconds, thus exhibiting a time course similar to the myogenic response described by Kontos et al 17 from pressure-flow studies in dog hindlimb and forelimb preparations. The time for onset of the response was also close to that reported by Smiesko 21 for the increase in blood flow following a 1-second decrease in pressure in perfused limb preparations (4.4 ± 0 . 3 seconds), but shorter than the average time reported by Sparks 23 for the increase in tension in response to quick stretch in isolated human umbilical artery strips (9.2 seconds).…”

Section: Discussionsupporting

confidence: 87%

“…3 seconds), but shorter than the average time reported by Sparks 23 for the increase in tension in response to quick stretch in isolated human umbilical artery strips (9.2 seconds). However, the duration of the responses described by Smiesko'and Sparks were much greater, averaging 25 ± 4 seconds in Smiesko's experiments 21 and 63.1 seconds in Sparks' experiments. 23 The average dilation observed after such an occlusion was generally about 2.5 to 3.5 /j.m, or to about 110% of control diameter.…”

Section: Discussionmentioning

confidence: 74%

“…Previous reports 21 ' 22 have also suggested that vascular smooth muscle exhibits rate-sensitive responses to stretch. Such responses might be important during a sudden increase in intravascular pressure.…”

Section: Discussionmentioning

confidence: 84%

“…21 - 24 For example, Smiesko-' 1 reported a sustained decrease in vascular resistance in response to the ascending part of a 1-second square wave change in perfusion pressure, and proposed a rate-sensitive vasodilator response. We did not observe any sustained vasodilation at upstream sites following brief occlusions.…”

Section: Discussionmentioning

confidence: 99%

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Relative contributions of passive and myogenic factors to diameter changes during single arteriole occlusion in the hamster cheek pouch.

Lombard¹,

Duling²

1977

Circulation Research

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SUMMARY To evaluate the relative influence of myogenic and passive effects on arteriolar dilation during interruption of blood flow, single arterioles of the suffused hamster cheek pouch were occluded while diameters were measured upstream and downstream from the occlusion. Arteriolar pressures, measured by the servo null method, increased 22.5% upstream from the occlusion and decreased 34% downstream. Dilation upstream from occlusions was invariably greater than that downstream, even when suffusion solution PO 2 was increased to high levels that resulted in a decreased initial diameter and a reduction in the absolute increase in diameter during occlusion. In some experiments, arterioles were initially occluded for 60 seconds upstream or downstream from the point of observation; then this occlusion was abruptly released and was replaced by another on the other side of the observation site. Diameter increases upstream from occlusions were again greater than those downstream. Abrupt changes in diameter, apparently of a passive nature, were correlated with the shift in pipette position; however no secondary diameter changes indicating myogenic mechanisms were observed consistently during either high or low oxygen suffusion. The average dilation for all experiments (single and double occlusions) was to 134% of control at upstream sites and to 122% of control at downstream sites. Passive effects apparently contributed 6-12% to the diameter changes during occlusion. Transient diameter changes following brief occlusions suggested that the arterioles may be capable of myogenic responses; however, passive and metabolic factors are apparently predominant in determining the steady state response to longer occlusions.INCREASED transmural pressure in the peripheral vasculature may lead to two effects: passive distension or stretch-induced active contraction. The latter has been termed the myogenic response of the vasculature. The relative importance of the myogenic response of vascular smooth muscle to the local regulation of blood flow has been debated since it was first proposed by Bayliss in 1902. "3 It has been assumed that stretch activation of smooth muscle would occur with increased transmural pressure, induce a vasoconstriction and increased vascular resistance, and thus stabilize blood flow. Conversely, a decrease in intravascular pressure would cause vasodilation and decreased resistance to blood flow. The myogenic mechanism has been invoked to explain the moment-tomoment control of blood flow, The magnitude of the hyperemic flow following release of an occlusion depends upon the vasodilation occurring during the period of interrupted flow.3 Therefore, measurement of the changes in arteriolar diameter during occlusion should be a sensitive indicator of the factors influencing the responses of the vessels to interruption of blood flow. The purpose of this investigation was to assess, by observation of the behavior of individual arterioles, the relative importance of passive and myogenic factors in determining the v...

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Section: Discussionsupporting

confidence: 87%

Section: Discussionmentioning

confidence: 74%

Section: Discussionmentioning

confidence: 84%

Section: Discussionmentioning

confidence: 99%

See 2 more Smart Citations

Relative contributions of passive and myogenic factors to diameter changes during single arteriole occlusion in the hamster cheek pouch.

Lombard¹,

Duling²

1977

Circulation Research

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“…Such upward or downward shift in the pressure range of autoregulation suggests the possibility of bidirectional responses in the myogenic mechanism. It is probably caused by the residual vascular tone with positive and negative stretch stimuli (SMIEsKO, 1971;GRANDE and MELLANDER, 1978) and may originate from a membrane event (Ca2 +-influx and -efflux) in smooth muscle cells. The myogenic response was also mild in dog intestine-mesenteric vascular beds.…”

Section: Discussionmentioning

confidence: 99%

Effects of venous pressure elevation on myogenic vasoconstrictive responses to static and dynamic arterial pressures.

Iida

Mitamura

1989

Jpn.J.Physiol

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In order to establish the nature of the stretch-evoked dynamic properties of vascular smooth muscle in arterioles, we have examined the static and dynamic effects of both arterial pulse pressure and elevated venous pressure on the resistance vessels (arteries and arterioles) in an intestinal mesenteric preparation derived from dogs. The dynamic myogenic response to stretch stimuli was directly related to both the frequency of arterial pulse pressure (1-20 c/min) and the level of venous pressure (0-45 mmHg). Under elevated venous pressure (20 mmHg), the mean arterial flow decreased with an increase in the frequency of arterial pulse pressure. The arteriolar vascular tone (namely, vascular resistance) was seen to be enhanced. We found that elevated venous pressure promotes active constriction (9-53%) of arteriolar smooth muscle (myogenic mechanism). The elevation of venous pressure also caused a rhythmic constriction (vasomotion) in the site of both vein and artery, which was completely abolished by an a-blocker (phentolamine). The results suggest that during venous pressure elevation a very pronounced myogenic constriction in terminal arterioles is caused by either a local neural reflex or a propagated myogenic response in the arteriolar network.

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The Myogenic Response

Johnson

1980

Comprehensive Physiology

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Unidirectional rate sensitivity component in local control of vascular tone

Cited by 23 publications

References 21 publications

Relative contributions of passive and myogenic factors to diameter changes during single arteriole occlusion in the hamster cheek pouch.

Relative contributions of passive and myogenic factors to diameter changes during single arteriole occlusion in the hamster cheek pouch.

Effects of venous pressure elevation on myogenic vasoconstrictive responses to static and dynamic arterial pressures.

The Myogenic Response

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