Types of potassium channels involved in coronary reactive hyperemia depend on duration of preceding ischemia in rat hearts

Shinoda, Masanori; Toki, Yukio; Murase, Kouhei; Mokuno, Shinji; Okumura, Kenji; Itō, Takayuki

doi:10.1016/s0024-3205(97)00604-8

Cited by 14 publications

(22 citation statements)

References 22 publications

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“…Reactive-hyperemia to 5 min vascular occlusion is inhibited by both TEA and charybdotoxin in isolated rat hearts (1302). Block of BK Ca channels with TEA in the pig coronary circulation resulted in a decrease in resting vascular conductance and a decrease in exercise-induced hyperemia (996).…”

Section: Bkca Channelsmentioning

confidence: 99%

“…Glibenclamide also inhibited reactive hyperemia induced by 15 to 120 s occlusion in canine coronary circulation, in vivo (73, 128, 262, 352, 654, 728, 780, 1569). Similarly, glibenclamide inhibits reactive hyperemia induced by 30 s occlusion in isolated rat hearts (1302). Reactive hyperemia also was reduced by 30% after 5 min occlusion in pig hearts, in vivo (1605).…”

Section: Katp Channelsmentioning

confidence: 99%

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Smooth Muscle Ion Channels and Regulation of Vascular Tone in Resistance Arteries and Arterioles

Tykocki

Boerman

Jackson

2017

Comprehensive Physiology

269

347

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Vascular tone of resistance arteries and arterioles determines peripheral vascular resistance, contributing to the regulation of blood pressure and blood flow to, and within the body’s tissues and organs. Ion channels in the plasma membrane and endoplasmic reticulum of vascular smooth muscle cells (SMCs) in these blood vessels importantly contribute to the regulation of intracellular Ca2+ concentration, the primary determinant of SMC contractile activity and vascular tone. Ion channels provide the main source of activator Ca2+ that determines vascular tone, and strongly contribute to setting and regulating membrane potential, which, in turn, regulates the open-state-probability of voltage gated Ca2+ channels (VGCCs), the primary source of Ca2+ in resistance artery and arteriolar SMCs. Ion channel function is also modulated by vasoconstrictors and vasodilators, contributing to all aspects of the regulation of vascular tone. This review will focus on the physiology of VGCCs, voltage-gated K+ (KV) channels, large-conductance Ca2+-activated K+ (BKCa) channels, strong-inward-rectifier K+ (KIR) channels, ATP-sensitive K+ (KATP) channels, ryanodine receptors (RyRs), inositol 1,4,5-trisphosphate receptors (IP3Rs), and a variety of transient receptor potential (TRP) channels that contribute to pressure-induced myogenic tone in resistance arteries and arterioles, the modulation of the function of these ion channels by vasoconstrictors and vasodilators, their role in the functional regulation of tissue blood flow and their dysfunction in diseases such as hypertension, obesity, and diabetes.

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Section: Bkca Channelsmentioning

confidence: 99%

Section: Katp Channelsmentioning

confidence: 99%

Smooth Muscle Ion Channels and Regulation of Vascular Tone in Resistance Arteries and Arterioles

Tykocki

Boerman

Jackson

2017

Comprehensive Physiology

269

347

View full text Add to dashboard Cite

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“…PORH refers to the phenomenon of increased BF that follows relief of ischaemia and is a result of dilation of resistance vessels. This vasodilation has been attributed to myogenic relaxation of the vessels [20] and local release of mediators and metabolites such as adenosine [21], prostaglandins and nitric oxide [1,22]. Measuring PORH is frequently used to evaluate structural changes in the circulation [23].…”

Section: Introductionmentioning

confidence: 99%

Reproducibility of blood flow and post-occlusive reactive hyperaemia as measured by venous occlusion plethysmography

et al. 2005

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Venous occlusion plethysmography is commonly used as a tool to assess BF (blood flow) and VR (vascular resistance) at baseline and during PORH (post-occlusive reactive hyperaemia). However, little is known about the reproducibility of this method. The purpose of the present study was to investigate short- (hours) and medium (week)-term reproducibility of forearm, calf and thigh BF and VR at baseline and during PORH. Reproducibility was assessed by the CV (coefficient of variation). In eight subjects, baseline BF and VR of the forearm, calf and thigh were measured using venous occlusion plethysmography (50 mmHg). PORH and minimal VR were measured after 13 min of arterial occlusion (220 mmHg). Reproducibility of baseline forearm and calf BF was acceptable and in agreement with previous studies (CV, 12.9-21.2%). Short- and medium-term reproducibility of thigh BF was good (CV, 5.9% and 8.7% respectively). Baseline VR showed acceptable-to-good reproducibility for forearm, calf and thigh (8.3-22.5%). Forearm PORH showed a CV of 6.1% (short term) and 8.6% (medium term); this was 6.1% (short term) and 6.4% (medium term) for the calf and 6.4% (short term) and 8.0% (medium term) for the thigh. Minimal VR showed good-to-acceptable reproducibility (CV, 6.1-11.7%). In conclusion, forearm, calf and thigh BF and PORH measured by plethysmography have an acceptable-to-good short- and medium-term reproducibility. Short- and medium-term reproducibility of forearm and calf baseline BF are acceptable and thigh baseline BF has a good short- and medium-term reproducibility. Therefore plethysmography is a suitable low-cost tool to assess thigh baseline BF and PORH.

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“…TEA is a non-selective K + channel blocker; thus it can block calcium-activated K + channels (K ca ) at concentrations as low as 1 m M [32] . However, high concentrations may be required to block other voltage-dependent K + channels, such as K ATP channels, because a TEA concentration of 20 m M is typically used for in vitro electrophysiology experiments [33,34] . Therefore, the proliferative inhibition of TEA may be due to the blockade of K ca channels, while the blockade of other voltage-dependent K + channels, such as the K ATP channels, may contribute to the apoptotic effect.…”

Section: Discussionmentioning

confidence: 99%

Tetraethylammonium Inhibits Glioma Cells via Increasing Production of Intracellular Reactive Oxygen Species

Yang¹,

Liu²,

Hu³

et al. 2009

Chemotherapy

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Background: Potassium channel blockers have been shown to possess antitumor properties, but the role of apoptosis remains to be clarified. In this study, we investigated the antiproliferative effect of tetraethylammonium (TEA), a nonspecific potassium channel blocker, in rat C6 and 9L glioma cells. Methods: Cytotoxicity was evaluated by MTT assay. Apoptosis was detected by TUNEL and annexin V-FITC/propidium iodide assays. Protein levels were determined by Western blot analysis. Intracellular reactive oxygen species (ROS) levels were assessed flow cytometrically. Results: TEA (2–60 mM) significantly inhibited the proliferation of C6 and 9L glioma cells. In addition, increased cell apoptosis was confirmed after treatment with 40 mM TEA. Apoptosis was associated with a dramatic increase in ROS levels and altered Bcl-2/Bax protein balance. Conclusion: TEA can inhibit proliferation and induce apoptosis in both cell lines; therefore, it might be associated with the increase in intracellular ROS production.

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Types of potassium channels involved in coronary reactive hyperemia depend on duration of preceding ischemia in rat hearts

Cited by 14 publications

References 22 publications

Smooth Muscle Ion Channels and Regulation of Vascular Tone in Resistance Arteries and Arterioles

Smooth Muscle Ion Channels and Regulation of Vascular Tone in Resistance Arteries and Arterioles

Reproducibility of blood flow and post-occlusive reactive hyperaemia as measured by venous occlusion plethysmography

Tetraethylammonium Inhibits Glioma Cells via Increasing Production of Intracellular Reactive Oxygen Species

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