Remodelling and Enhanced Myogenic Tone in Cerebral Resistance Arteries Isolated from Genetically Hypertensive Brattleboro Rats

1998 ◽  
Vol 35 (1) ◽  
pp. 18-26 ◽  
Author(s):  
William R. Dunn ◽  
Sarah J. Wallis ◽  
Sheila M. Gardiner
Keyword(s):  
Myogenic Tone ◽  
Brattleboro Rats ◽  
Resistance Arteries ◽  
Cerebral Resistance ◽  
Genetically Hypertensive

Enhanced resistance artery sensitivity to agonists under isobaric compared with isometric conditions

1994 ◽  
Vol 266 (1) ◽  
pp. H147-H155 ◽  
Author(s):  
W. R. Dunn ◽  
G. C. Wellman ◽  
J. A. Bevan
Keyword(s):  
Membrane Potential ◽  
Angiotensin Ii ◽  
Myogenic Tone ◽  
Isometric Contractions ◽  
Fundamental Interaction ◽  
Resistance Artery ◽  
Resistance Arteries ◽  
Enhanced Resistance ◽  
Increased Sensitivity

We have compared the responsiveness of rabbit mesenteric resistance arteries with agonists under isometric and isobaric conditions. When pressurized (60 mmHg), arteries spontaneously reduced their diameter by 18.1%. An equivalent isometric stress did not generate force in a “wire” myograph. Subsequently, much higher concentrations of norepinephrine (NE) and histamine were required to cause isometric contractions than were needed to reduce vascular diameter of pressurized vessels, whereas angiotensin II produced a maintained response only in pressurized arteries. Reducing transmural pressure to 20 mmHg abolished pressure-induced myogenic tone and decreased arterial sensitivity to NE. Under isometric conditions, partial depolarization with KCl increased sensitivity to NE and histamine to within the concentration range effective in pressurized vessels and also "revealed" responses to angiotensin II. The membrane potential of the vascular smooth muscle cells under partially depolarized conditions was similar to that found in vivo and in vessels studied isobarically. These observations demonstrate a fundamental interaction between pressure-induced myogenic tone and the sensitivity of resistance arteries to vasoactive stimuli. This influence was mimicked in isometrically mounted vessels by partial depolarization, indicating a possible pivotal role for membrane potential in determining the reactivity of the resistance vasculature.

Pressure-Induced Myogenic Responses in Human Isolated Cerebral Resistance Arteries

Stroke ◽  
1996 ◽  
Vol 27 (12) ◽  
pp. 2287-2291 ◽  
Author(s):  
Sarah J. Wallis ◽  
John Firth ◽  
William R. Dunn
Keyword(s):  
Resistance Arteries ◽  
Myogenic Responses ◽  
Cerebral Resistance

Abstract 485: Novel Mechanisms at Immune-vascular Interfaces Regulates Myogenic Tone of Resistance Arteries and Induce Hypertension in Mice

2018 ◽  
Vol 38 (Suppl_1) ◽  
Author(s):  
Daniela Carnevale ◽  
Iolanda Vinciguerra ◽  
Manuel Casaburo ◽  
Marialuisa Perrotta ◽  
Roberta Iacobucci ◽  
...  
Keyword(s):  
Myogenic Tone ◽  
Resistance Arteries

scholarly journals Caveolin-1 and caveolin-3 regulate Ca2+ homeostasis of single smooth muscle cells from rat cerebral resistance arteries

2007 ◽  
Vol 293 (1) ◽  
pp. H204-H214 ◽  
Author(s):  
T. Kamishima ◽  
T. Burdyga ◽  
J. A. Gallagher ◽  
J. M. Quayle
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Removal Rate ◽  
Muscle Cells ◽  
Amino Acid Residues ◽  
Resistance Arteries ◽  
Inhibitory Peptide ◽  
Caveolin 1 ◽  
Domain Peptide ◽  
Cerebral Resistance

The role of caveolins, signature proteins of caveolae, in arterial Ca2+ regulation is unknown. We investigated modulation of Ca2+ homeostasis by caveolin-1 and caveolin-3 using smooth muscle cells from rat cerebral resistance arteries. Membrane current and Ca2+ transients were simultaneously measured with voltage-clamped single cells. Membrane depolarization triggered Ca2+ current and increased intracellular Ca2+ concentration ([Ca2+]i). After repolarization, elevated [Ca2+]i returned to the resting level. Ca2+ removal rate was determined from the declining phase of the Ca2+ transient. Application of caveolin-1 antibody or caveolin-1 scaffolding domain peptide, corresponding to amino acid residues 82–101 of caveolin-1, significantly slowed Ca2+ removal rate at a measured [Ca2+]i of 250 nM, with little effect at a measured [Ca2+]i of 600 nM. Application of caveolin-3 antibody or caveolin-3 scaffolding domain peptide, corresponding to amino acid residues 55–74 of caveolin-3, also significantly slowed Ca2+ removal rate at a measured [Ca2+]i of 250 nM, with little effect at a measured [Ca2+]i of 600 nM. Likewise, application of calmodulin inhibitory peptide, autocamtide-2-related inhibitory peptide, and cyclosporine A, inhibitors for calmodulin, Ca2+/calmodulin-dependent protein kinase II, and calcineurin, also significantly inhibited Ca2+ removal rate at a measured [Ca2+]i of 250 nM but not at 600 nM. Application of cyclopiazonic acid, a sarcoplasmic reticulum Ca2+ ATPase inhibitor, also significantly inhibited Ca2+ removal rate at a measured [Ca2+]i of 250 nM but not at 600 nM. Our results suggest that caveolin-1 and caveolin-3 are important in Ca2+ removal of resistance artery smooth muscle cells.

Effects of Age and Exercise Training on Nitric Oxide Bioavailability in Cerebral Resistance Arteries

2006 ◽  
Vol 38 (Suppl 1) ◽  
pp. S4
Author(s):  
Rafael A. Reyes ◽  
Kathryn E. Nichol ◽  
Scott A. Spier ◽  
Amanda LeBlanc ◽  
Judy Muller-Delp
Keyword(s):  
Nitric Oxide ◽  
Exercise Training ◽  
Resistance Arteries ◽  
Cerebral Resistance ◽  
Nitric Oxide Bioavailability

Role of T-type calcium channels in myogenic tone of skeletal muscle resistance arteries

2002 ◽  
Vol 283 (6) ◽  
pp. H2239-H2243 ◽  
Author(s):  
Ed VanBavel ◽  
Oana Sorop ◽  
Ditte Andreasen ◽  
Martin Pfaffendorf ◽  
Boye L. Jensen
Keyword(s):  
Calcium Channels ◽  
Southern Blotting ◽  
Myogenic Tone ◽  
Cremaster Muscle ◽  
Resistance Arteries ◽  
Rt Pcr ◽  
Response Curves ◽  
Potent Effect ◽  
Channel Expression

T-type calcium channels may be involved in the maintenance of myogenic tone. We tested their role in isolated rat cremaster arterioles obtained after CO2anesthesia and decapitation. Total RNA was analyzed by RT-PCR and Southern blotting for calcium channel expression. We observed expression of voltage-operated calcium (CaV) channels CaV3.1 (T-type), CaV3.2 (T-type), and CaV1.2 (L-type) in cremaster arterioles ( n= 3 rats). Amplification products were observed only in the presence of reverse transcriptase and cDNA. Concentration-response curves of the relatively specific L-type blocker verapamil and the relatively specific T-type blockers mibefradil and nickel were made on cannulated vessels with either myogenic tone (75 mmHg) or a similar level of constriction induced by 30 mM K+ at 35 mmHg. Mibefradil and nickel were, respectively, 162-fold and 300-fold more potent in inhibiting myogenic tone compared with K+-induced constriction [log(IC50, M): mibefradil, basal −7.3 ± 0.2 ( n = 9) and K+ −5.1 ± 0.1 ( n = 5); nickel, basal −4.1 ± 0.2 ( n = 5) and K+ −1.6 ± 0.5 ( n = 5); means ± SE]. Verapamil had a 17-fold more potent effect [log(IC50, M): basal −6.6 ± 0.1 ( n = 5); K+ −5.4 ± 0.3 ( n = 4); all log(IC50) P < 0.05, basal vs. K+]. These data suggest that T-type calcium channels are expressed and involved in maintenance of myogenic tone in rat cremaster muscle arterioles.

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