An analysis of excitatory junctional potentials recorded from arterioles.

Hirst, G. D. S.; Neild, T O

doi:10.1113/jphysiol.1978.sp012374

Cited by 174 publications

(217 citation statements)

References 17 publications

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“…Because many observations have revealed an exponential decay of the conducted electrical signal, it was proposed that longitudinal spread of vasomotor responses reflects the passive, electrotonic conduction of changes in membrane potential via gap junctions connecting cells of the vessel wall (Pacicca et al, 1996;Welsh & Segal, 1998;Gustafsson & Holstein-Rathlou, 1999). Therefore, the decay of the conducted vasomotor responses along the vessel length should be consistent with the length constant estimated from electrotonic potentials produced by current injection into the smooth muscle or endothelial cells of arterioles, which is between 0.9 and 1.6 mm (Hirst & Neild, 1978;Hirst et al, 1997;Emerson et al, 2002).…”

Section: Conduction Of Vasomotor Responsesmentioning

confidence: 94%

Control and Coordination of Vasomotor Tone in the Microcirculation

Lillo¹,

Franco²,

Puebla³

et al. 2012

The Cardiovascular System - Physiology, Diagnostics and Clinical Implications

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Section: Conduction Of Vasomotor Responsesmentioning

confidence: 94%

Control and Coordination of Vasomotor Tone in the Microcirculation

Lillo¹,

Franco²,

Puebla³

et al. 2012

The Cardiovascular System - Physiology, Diagnostics and Clinical Implications

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“…Conducted responses may form the base for spatial coordination of local vasomotor responses 2. Conduction of both vasoconstriction and vasodilation in vascular networks has been described,3 and the mechanisms through which these occur are subject of ongoing studies. It has been shown that changes in membrane potential (hyper‐ or depolarization) resulting from local stimuli can propagate intercellularly mainly along the endothelial cells, but also along the smooth muscle cell layers of arteries 4.…”

Section: Introductionmentioning

confidence: 99%

Sustained conduction of vasomotor responses in rat mesenteric arteries in a two‐compartment in vitro set‐up

et al. 2018

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AimConduction of vasomotor responses may contribute to long‐term regulation of resistance artery function and structure. Most previous studies have addressed conduction of vasoactivity only during very brief stimulations. We developed a novel set‐up that allows the local pharmacological stimulation of arteries in vitro for extended periods of time and studied the conduction of vasomotor responses in rat mesenteric arteries under those conditions.MethodsThe new in vitro set‐up was based on the pressure myograph. The superfusion chamber was divided halfway along the vessel into two compartments, allowing an independent superfusion of the arterial segment in each compartment. Local and remote cumulative concentration‐response curves were obtained for a range of vasoactive agents. Additional experiments were performed with the gap junction inhibitor 18β‐glycyrrhetinic acid and in absence of the endothelium.ResultsPhenylephrine‐induced constriction and acetylcholine‐induced dilation were conducted over a measured distance up to 2.84 mm, and this conduction was maintained for 5 minutes. Conduction of acetylcholine‐induced dilation was inhibited by 18β‐glycyrrhetinic acid, and conduction of phenylephrine‐induced constriction was abolished in absence of the endothelium. Constriction in response to high K+ was not conducted. Absence of remote stimulation dampened the local response to phenylephrine.ConclusionThis study demonstrates maintained conduction of vasoactive responses to physiological agonists in rat mesenteric small arteries likely via gap junctions and endothelial cells, providing a possible mechanism for the sustained functional and structural control of arterial networks.

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“…A blood vessel can be approximated from the electrical point of view as a cable with certain membrane and internal conductances [146,161]. In a passive linear cable with infinite length, the steady-state spread of a local potential change is attenuated exponentially:…”

Section: Length Constantsmentioning

confidence: 99%

“…The vessel model was reduced to two dimensions (axial and radial) on the assumption that concentration and potential gradients in the circumferential direction are negligible [147]. These gradients should be minimal during circumferentially uniform stimulations, but are small even during local stimulation with an intracellular microelectrode [146]. In this study we assume that an EC spans 15 SMCs and vice versa.…”

Section: Multicellular Vessel Modelmentioning

confidence: 99%

“…The electrical equivalent of the model vessel is shown in Figure 3.3. We assumed electrically sealed ends [146], small intracellular and extracellular resistances, and negligible effect of tight junctions between ECs. The model assumes that the individual ECs and SMCs are isopotential [149], and without intracellular concentration gradients.…”

Section: Multicellular Vessel Modelmentioning

confidence: 99%

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Theoretical Investigations of Communication in the Microcirculation: Conducted Responses, Myoendothelial Projections and Endothelium Derived Hyperpolarizing Factor

Nagaraja¹

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This dissertation, written by Sridevi Nagaraja, and entitled Theoretical investigations of intercellular communication in the microcirculation: conducted responses, myoendothelial projections and endothelium derived hyperpolarizing factor, having been approved in respect to style and intellectual content, is referred to you for judgment.We have read this dissertation and recommend that it be approved. _______________________________________Wei-Chiang Lin dynamics in vascular cells in single as well as multicellular models. Advancement of these models is necessary to achieve the level of sophistication analogous to cardiac models. These models will contribute towards the development of a theoretical framework for the understanding of microcirculatory phenomena. It is also one of the most thoroughly studied vascular beds with vast amount of experimental data available. Therefore, in most of our models we use data from small rat mesenteric arteries (RMAs). This section describes the major channels and pumps present within the cytosol in the longitudinal direction of the cell.Through this process, it has become obvious that detailed models of Ca is still a need to build upon previous modeling work in order to develop cellular models that will assist in the investigations of vascular tone regulation in health and disease. Other channels specific to EC are described below. Inward rectifier potassium channelsInward rectifier potassium channels (K ir ) are sensitive to extracellular concentration of potassium in the range of 1 to 20 mM. These channels increase entry of potassium into the cell thereby hyperpolarizing of EC and subsequently the SMC. They are present in almost all endothelial cells and contribute towards the resting V m of the EC. EC K ir channels are known to be activated not only by potassium but also by shear stress. Theoretical modeling of vascular ECsThe first endothelial cell models were based on earlier generic models of Ca Endothelium derived controllers Nitric oxideNitric oxide was identified as the endothelium derived relaxing factor in 1980 ProstacyclinProstacyclin (PGI2) in rat mesenteric arterioles, PGI2 does not exert a hyperpolarizing effect. The involvement of PGI2 pathways is usually studied using COX inhibitor (Indomethacin). Endothelium derived hyperpolarizing factorEDHF is an endothelium derived non-nitric oxide (NO) and non-cyclicoxygenase and EC hyperpolarization by activation of IK Ca and SK Ca is now a widely accepted finger print of EDHF action across many studies.However, its propagation to the SMC is still being investigated. Myoendothelial feedbackStudies have shown that endothelium derived pathways can also be induced during SMC stimulation which brought about the concept of myoendothelial feedback. where R gj is gap junction resistance, and ∆V gj represents V m cells n-th and m-th ( Figure 2.2). where P gj,S is the gap junction permeability to S (e.g., Ca rectification is low at physiological concentration gradients, and a simpler linear approximation can ...

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An analysis of excitatory junctional potentials recorded from arterioles.

Cited by 174 publications

References 17 publications

Control and Coordination of Vasomotor Tone in the Microcirculation

Control and Coordination of Vasomotor Tone in the Microcirculation

Sustained conduction of vasomotor responses in rat mesenteric arteries in a two‐compartment in vitro set‐up

Theoretical Investigations of Communication in the Microcirculation: Conducted Responses, Myoendothelial Projections and Endothelium Derived Hyperpolarizing Factor

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