Patch and whole-cell voltage clamp of single mammalian visceral and vascular smooth muscle cells

1985 ◽  
Vol 41 (7) ◽  
pp. 887-894 ◽  
Author(s):  
T. B. Bolton ◽  
R. J. Lang ◽  
T. Takewaki ◽  
C. D. Benham
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Voltage Clamp ◽  
Vascular Smooth Muscle Cells ◽  
Cell Voltage ◽  
Muscle Cells ◽  
Whole Cell ◽  
Whole Cell Voltage Clamp

Stretch-activated single-channel and whole cell currents in vascular smooth muscle cells

1992 ◽  
Vol 262 (4) ◽  
pp. C1083-C1088 ◽  
Author(s):  
M. J. Davis ◽  
J. A. Donovitz ◽  
J. D. Hood
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Single Channel ◽  
Muscle Cells ◽  
Cation Channel ◽  
Nonselective Cation Channel ◽  
Whole Cell ◽  
Cell Stretch

Mechanosensitive ion channels may play a key role in transducing vascular smooth muscle (VSM) stretch into active force development. To test this hypothesis, we recorded single-channel and macroscopic currents during mechanical stimulation of enzymatically dispersed vascular smooth muscle cells. Patch pipette suction activated a nonselective cation channel that was permeable to K+, Na+, and Ca2+. Whole cell stretch was accomplished using two patch-type micropipettes attached to the cell ends with suction. Stretch elicited a sustained depolarization with a magnitude similar to that observed in pressurized arteries. Under whole cell voltage clamp, stretch activated an inward current with a reversal potential near -15 mV. In another series of experiments, whole cell stretch failed to modify the current-voltage relationship for voltage-gated calcium currents. Thus, in VSM, both single-channel and whole cell data are consistent with activation of a nonselective cation channel by stretch. This mechanism may, in part, account for pressure-induced activation of intact blood vessels.

scholarly journals Vasorelaxing Action of Vasonatrin Peptide is Associated with Activation of Large-Conductance Ca2+-activated Potassium Channels in Vascular Smooth Muscle Cells

2010 ◽  
pp. 187-194
Author(s):  
J Yu ◽  
M Zhu ◽  
Z Fu ◽  
X Zhu ◽  
Y Zhao ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Patch Clamp ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Radial Artery ◽  
Vascular Smooth Muscle Cells ◽  
Guanylyl Cyclase ◽  
Muscle Cells ◽  
Whole Cell ◽  
Rat Mesenteric Artery

The aim of this study was to test the hypothesis that vasorelaxing action of vasonatrin peptide (VNP) is due to activation of the large-conductance Ca2+-activated potassium channel (BKCa) via guanylyl cyclase (GC)-coupled natriuretic peptide receptors (NPRs) in vascular smooth muscle cells (VSMCs). Contraction experiments were performed using human radial artery, whereas BKCa current by patch clamp was recorded in cells from rat mesenteric artery. Contractility of rings cut from human radial artery was detected in vitro. As a result, VNP induced a dose-dependent vasorelaxation of human radial artery, which could be mimicked by 8-Br-cGMP, and suppressed by TEA, a blocker of BKCa, HS-142-1, a blocker of GC-coupled NPRs, or methylene blue (MB), a selective inhibitor of guanylyl cyclase. Sequentially, whole-cell K+ currents were recorded using patch clamp techniques. BKCa current of VSMCs isolated from rat mesentery artery was obtained by subtracting the whole cell currents after applications of 10-7 mol/l iberiotoxin (IBX) from before its applications. In accordance with the results of arterial tension detection, BKCa current was significantly magnified by VNP, which could also be mimicked by 8-Br-cGMP, whereas suppressed by HS-142-1, or MB. Taken together, VNP acts as a potent vasodilator, and NPRA/B-cGMP-BKCa is one possible signaling system involved in VNP induced relaxation.

Electrical properties and morphology of single vascular smooth muscle cells in culture

1986 ◽  
Vol 251 (5) ◽  
pp. C763-C773 ◽  
Author(s):  
L. Toro ◽  
A. Gonzalez-Robles ◽  
E. Stefani
Keyword(s):  
Smooth Muscle ◽  
Cell Membrane ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Voltage Clamp ◽  
Vascular Smooth Muscle Cells ◽  
Muscle Cells ◽  
K Channels ◽  
Caudal Artery ◽  
Intracellular Microelectrodes

Single vascular smooth muscle cells (VSMC) were isolated from the caudal artery and vein and studied after 2 or 3 days in culture. Current clamp with intracellular microelectrodes and "whole-cell" voltage-clamp techniques were used. Also, scanning and transmission electron microscopy studies were performed, revealing morphological characteristics of smooth muscle in culture. Cells could contract in response to electrical and chemical stimuli. The passive membrane properties recorded with intracellular microelectrodes in a mammalian saline were as follows: 1) for artery, resting potential Vm = -56 +/- 5 mV (mean +/- SD), input resistance Rin = 590 +/- 35 M omega, membrane time constant tau m = 19 +/- 2 ms, membrane capacity C/cm2 = 1.3 +/- 0.2 microF/cm2, and length constant lambda = 900 +/- 40 micron; and 2) for vein, Vm = -66 +/- 3 mV, Rin = 450 +/- 25 M omega, tau m = 19 +/- 2 ms, C/cm2 = 1.0 +/- 0.1 microF/cm2, and lambda = 1,300 +/- 200 micron. The values calculated for a short cable and the observed change of the membrane potential as a single exponential, in response to hyperpolarizing pulses of current, both indicate that the cell membrane behaves as an isopotential surface. With hyperpolarizing pulses, both cell types gave linear voltage-current (V-I) relationships with a constant slope, Rin. On the other hand, depolarizing pulses elicited outward rectification. Voltage-clamp experiments show an outward voltage-dependent K+ current (IK) when the cell membrane is depolarized beyond approximately equal to -40 mV from holding levels approximately equal to -60 mV. Maximum slope conductances were of approximately 120 microS/cm2. Blocking of K+ channels with tetraethylammonium ions did not unmask an inward current. These results indicate that VSMC from rat caudal artery and vein in culture have K+ channels responsible for the graded depolarization of the cell membrane in response to an electrical stimulus. Furthermore, this experimental approach seems to be adequate to further study the electrical responses of VSMC from vessels at distinct stages of development, and to follow these responses as the cells change in a defined environment.

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