Changes in resting membrane potential induced by active sensitization in the guinea-pig vas deferens

1998 ◽  
Vol 76 (7-8) ◽  
pp. 802-806 ◽  
Author(s):  
J Noireaud ◽  
O Souilem ◽  
S Baudet ◽  
J -C Bidon ◽  
M Gogny ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Membrane Potential ◽  
Guinea Pig ◽  
Smooth Muscle Cells ◽  
Vas Deferens ◽  
Smooth Muscles ◽  
Muscle Cells ◽  
Resting Membrane Potential ◽  
Ouabain Binding

Smooth muscles hyperresponsiveness is a common feature in anaphylaxis and allergic diseases. The aim of the present work was to investigate whether the enhanced reactivity of sensitized guinea-pig vas deferens was associated with changes in the resting membrane potential (Er) of the smooth muscle cells. Active sensitization was performed by subcutaneous injection of egg albumen. Er was measured in vitro in isolated vas deferens with conventional KCl-filled microelectrodes. Quantification of [3H]ouabain binding sites, measurements of 86Rb efflux, and measurements of Na and K contents were also performed. In normal physiological solution, at 35°C, Er was a mean of -54.1 ± 0.3 mV (mean ± SEM) in control vas deferens. Sensitization resulted in depolarizing Er by about 7 mV. In control and sensitized preparations, the 3H-ouabain binding site concentration, the efflux of 86Rb, and the K content were similar. In guinea-pig vas deferens, active sensitization induced a partial depolarization of the resting membrane potential of the smooth muscle cells, which did not result from a downregulation of Na+-K+ pump sites.Key words: hyperreactivity, sensitization, Na+-K+ ATPase, guinea-pig, vas deferens, smooth muscle.

scholarly journals THE NERVOUS ENVIRONMENT OF INDIVIDUAL SMOOTH MUSCLE CELLS OF THE GUINEA PIG VAS DEFERENS

1968 ◽  
Vol 37 (3) ◽  
pp. 794-817 ◽  
Author(s):  
Neil C. R. Merrillees
Keyword(s):  
Smooth Muscle ◽  
Guinea Pig ◽  
Smooth Muscle Cells ◽  
Vas Deferens ◽  
Close Contact ◽  
Muscle Fibers ◽  
Smooth Muscles ◽  
Muscle Cells ◽  
Sensory Innervation ◽  
Close Contacts

Smooth muscle cells of the external longitudinal coat of the guinea pig vas deferens were followed for 480 µ at 4.5-µ intervals. Muscle bundles and fibers interwove, facilitating intermuscular and neuromuscular contacts. The ribbon- or rodlike muscle cells were about 450 µ long, 3,000 µ3 in volume, and 4,500 µ2 in area. The thickened nuclear zone lay anywhere along the middle one-third of the cell. Intercellular distances were 500–800 A. Intrusions were rare, and tight-junctions absent. At any level in a field of 80 muscle fibers there were 10–15 nerve bundles, each containing several varicose axons. Bundles and axons divided. Axons, en passage, were frequently within 500–1,000 A of a muscle fiber. En passage close contacts were rate. Axon terminations were bare, and bare axons invariably terminated. Bare terminations had scattered vesicle-laden varicosities and were from 10µ-60 µ in length, and all ended within 500 A of muscle fibers. Some made close contact with muscle fibers. Less than half of the muscle cells received this close contact, but some cells were approached by more than one termination. Most terminations involved more than one cell. Some cells had little or no innervation. Some groups of cells had a rich innervation. There was very little evidence of sensory innervation. These conclusions are not valid for other smooth muscles.

scholarly journals Local Ca2+transients and distribution of BK channels and ryanodine receptors in smooth muscle cells of guinea-pig vas deferens and urinary bladder

2001 ◽  
Vol 534 (2) ◽  
pp. 313-326 ◽  
Author(s):  
Yoshiaki Ohi ◽  
Hisao Yamamura ◽  
Norihiro Nagano ◽  
Susumu Ohya ◽  
Katsuhiko Muraki ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Urinary Bladder ◽  
Guinea Pig ◽  
Smooth Muscle Cells ◽  
Vas Deferens ◽  
Ryanodine Receptors ◽  
Muscle Cells ◽  
Bk Channels

Role of HERG-like K+ currents in opossum esophageal circular smooth muscle

1999 ◽  
Vol 277 (6) ◽  
pp. C1284-C1290 ◽  
Author(s):  
Hamid I. Akbarali ◽  
Hemant Thatte ◽  
Xue Dao He ◽  
Wayne R. Giles ◽  
Raj K. Goyal
Keyword(s):  
Smooth Muscle ◽  
Membrane Potential ◽  
Smooth Muscle Cells ◽  
Single Cells ◽  
Circular Muscle ◽  
Muscle Cells ◽  
Resting Membrane Potential ◽  
Channel Blockers ◽  
Circular Smooth Muscle ◽  
Inward Currents

An inwardly rectifying K+ conductance closely resembling the human ether-a-go-go-related gene (HERG) current was identified in single smooth muscle cells of opossum esophageal circular muscle. When cells were voltage clamped at 0 mV, in isotonic K+ solution (140 mM), step hyperpolarizations to −120 mV in 10-mV increments resulted in large inward currents that activated rapidly and then declined slowly (inactivated) during the test pulse in a time- and voltage- dependent fashion. The HERG K+ channel blockers E-4031 (1 μM), cisapride (1 μM), and La3+ (100 μM) strongly inhibited these currents as did millimolar concentrations of Ba2+. Immunoflourescence staining with anti-HERG antibody in single cells resulted in punctate staining at the sarcolemma. At membrane potentials near the resting membrane potential (−50 to −70 mV), this K+ conductance did not inactivate completely. In conventional microelectrode recordings, both E-4031 and cisapride depolarized tissue strips by 10 mV and also induced phasic contractions. In combination, these results provide direct experimental evidence for expression of HERG-like K+ currents in gastrointestinal smooth muscle cells and suggest that HERG plays an important role in modulating the resting membrane potential.

In vitro microelectrode study of the electrical properties of smooth muscle in equine ileum

2001 ◽  
Vol 149 (23) ◽  
pp. 707-711 ◽  
Author(s):  
N. P. H. Hudson ◽  
I. G. Mayhew ◽  
G. T. Pearson
Keyword(s):  
Smooth Muscle ◽  
Membrane Potential ◽  
Smooth Muscle Cells ◽  
Longitudinal Muscle ◽  
Muscle Cells ◽  
Muscle Layer ◽  
Potential Oscillations ◽  
Longitudinal Muscle Layer ◽  
Membrane Potential Oscillations

Intracellular microelectrode recordings were made from smooth muscle cells in cross-sectional preparations of equine ileum, superfused in vitro. Membrane potential oscillations and spike potentials were recorded in all preparations, but recordings were made more readily from cells in the longitudinal muscle layer than from cells in the circular layer. The mean (se) resting membrane potential (RMP) of smooth muscle cells in the longitudinal muscle layer was -51.9 (1.2) mV, and the membrane potential oscillations in this layer had a mean amplitude of 4.8 (0.4) mV, a frequency of 9.0 (0.1) cycles per minute and a duration of 5.8 (0.2) seconds. The membrane potential oscillations were preserved in the presence of tetrodotoxin. A waxing and waning pattern of membrane potential oscillation activity was observed. Nifedipine abolished the spiking contractile activity of the smooth muscle, did not abolish the membrane potential oscillations but did alter their temporal characteristics.

scholarly journals The Effect of Intracellular Current Pulses in Smooth Muscle Cells of the Guinea Pig Vas Deferens at Rest and during Transmission

1967 ◽  
Vol 50 (10) ◽  
pp. 2459-2475 ◽  
Author(s):  
M. R. Bennett
Keyword(s):  
Smooth Muscle ◽  
Guinea Pig ◽  
Action Potential ◽  
Smooth Muscle Cells ◽  
Vas Deferens ◽  
Electrical Coupling ◽  
Muscle Cells ◽  
Active Response ◽  
Current Pulses ◽  
Passive Response

The effect of intracellular current pulses on the membrane of smooth muscle cells of the guinea pig vas deferens at rest and during transmission was studied. Two main response types were identified: active response cells, in which a spike was initiated in response to depolarizing currents of sufficient strength and duration; passive response cells, in which depolarizing currents gave only electrotonic potential changes. These cells were three times more numerous than the active response cells. During the crest of the active response the input resistance fell by about 25% of the resting value. Comparison of the active response with the action potential due to stimulating the hypogastric nerve showed that the former was smaller in amplitude and had a slower rate of rise and higher threshold. Electrical coupling occurred between the smooth muscle cells during the propagation of the action potential. Depolarizing current pulses had no effect on the amplitude of the excitatory junction potential (E.J.P.) in passive response cells, but in general did decrease its amplitude in active response cells. These results are discussed with respect to the mechanism of autonomic neuroeffector transmission.

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