• Corpus ID: 12512359

Two types of Ca(2+)-channels in cells from the circular layer of guinea-pig ileum.

  title={Two types of Ca(2+)-channels in cells from the circular layer of guinea-pig ileum.},
  author={Dessislava B. Duridanova and Hristo S Gagov and Kiril K. Boev},
  journal={General physiology and biophysics},
  volume={12 4},
In this paper data are presented concerning some morphometrical characteristics and passive electrical properties of cell membranes from the circular layer of guinea-pig ileum (CC). The main purpose of the study has been to analyze the inward calcium current in these cells. Using the whole-cell voltage-clamp method the presence of T-like type of calcium channels (conducting low-threshold, fast inactivated, strictly potential-dependent and dihydropyridine-resistant calcium inward current--If… 

Figures and Tables from this paper

Three components of potassium outward current in cells isolated from the circular layer of guinea-pig ileum.
Three different populations of voltage-activated K+ channels were identified according to their voltage-dependences, inactivation kinetics and sensitivity toward selective K+ channels antagonists in
Impairment of Ca(2+) mobilization in circular muscle cells of the inflamed colon.
  • X. Shi, S. Sarna
  • Biology
    American journal of physiology. Gastrointestinal and liver physiology
  • 2000
It is concluded that the canine colonic circular muscle cells utilize Ca( 2+) influx through L-type channels as well as Ca(2+) release from the ryanodine- and IP(3)-sensitive stores to contract.
Physiological features of visceral smooth muscle cells, with special reference to receptors and ion channels.
The features of ion channels in vascular tissues only recently are reviewed, since this article makes only limited reference to vascular smooth muscle research.
Comparative studies of AJG049, a novel Ca2+ channel antagonist, on voltage‐dependent L‐type Ca2+ currents in intestinal and vascular smooth muscle
The effects of AJG049, a newly synthesized antagonist for regulation of gut motility, on voltage‐dependent L‐type Ca2+ channels, in vascular and intestinal smooth muscle are examined, comparing it with two other Ca2- channel antagonists, verapamil and diltiazem.
Verapamil reduces incidence of reentry during ventricular fibrillation in pigs.
Verapamil decreased the incidence of reentry in SDVF by accelerating conduction velocity to increase the likelihood of conduction block, possibly through increased sympathetic tone, and the drug slowed activation rate and conduction Velocity after 200 s of VF, suggesting that L-type Ca(++) channels remain active and may be important in the maintenance of LDVF.
Myostimulating effect of sesamum radiatum aqueous leaf extract in isolated Guinea-pig Taenia caeci contractile activity.
The spasmogenic effect induced by ESera could justify partially the use of S. radiatum as laxative in traditional medicine.


Inward current in single smooth muscle cells of the guinea pig taenia coli
Using the tight-seal voltage-clamp method, the ionic currents in the enzymatically dispersed single smooth muscle cells of the guinea pig taenia coli have been studied and the presence of multiple forms of Ca2+ channel is inferred from the inactivation characteristics, not from activation properties.
Characterization of ionic currents of circular smooth muscle cells of the canine pyloric sphincter.
There were no fundamental differences in the ionic currents recorded from circular muscle cells from the myenteric and submucosal regions, suggesting that the electrical activity of the tissue must be dependent upon structural characteristics (i.e. electrical coupling, fibre bundle dimensions, etc).
Some properties of Ca(2+)‐induced Ca2+ release mechanism in single visceral smooth muscle cell of the guinea‐pig.
The data are interpreted to suggest that the Ca(2+)‐induced Ca2+ release mechanism operates in single ileal cells in a regenerative manner.
Inactivation of calcium channels in single vascular and visceral smooth muscle cells of the guinea-pig.
It was concluded that the characteristics of Ca channel inactivation were changed by the removal of divalent cations from extracellular solution by the whole-cell patch-clamp method.
Two types of calcium channels in isolated smooth muscle cells from rat tail artery.
BAY K 8644 shifted the activation threshold, the peak inward current, and the steady-state inactivation-activation curves of L-type channel currents in the direction of hyperpolarization.
The calcium channel current of pregnant rat single myometrial cells in short‐term primary culture.
The passive and active electrical properties of pregnant rat single myometrial cells in short‐term primary culture were analysed using a single‐electrode voltage or current clamp and Ca2+ channel current inactivation was best fitted by a two‐exponential function.
Cyclopiazonic acid, an inhibitor of the sarcoplasmic reticulum Ca2+‐pump, reduces Ca2+‐dependent K+ currents in guinea‐pig smooth muscle cells
The results indicate that IK‐Ca is selectively and strongly suppressed by CPA, a specific inhibitor of the Ca2+‐ATPase in sarcoplamic reticulum (SR), on membrane ionic currents examined in single smooth muscle cells freshly isolated from ileal longitudinal strips and urinary bladder of the guinea‐pig.
Voltage-dependent calcium channels in smooth muscle cells.
Channels highly selective for calcium, which open when the membrane is depolarized, have been found in all smooth muscle cells examined, whether or not they can generate action potentials. The
A novel type of cardiac calcium channel in ventricular cells.
A novel type of cardiac Ca channel with several properties that distinguish it from the hitherto-identified Ca channel in heart cells is described, which activates and inactivates at relatively negative potentials and remains functional long after patch excision.
Two Types of Calcium Channels in Single Smooth Muscle Cells From Rabbit Ear Artery Studied With Whole‐Cell and Single‐Channel Recordings
It is concluded that vascular smooth muscle cells contain two types of calcium channels with properties very similar to those described for T- and L-type calcium channels in other cell types; the L current appears to be the predominant current component in whole-cell recordings.