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Literature DB >> 13357742

Changes in membrane characteristics of heart muscle during inhibition.

Abstract

Membrane characteristics were studied in isolated muscle strands from auricles of frogs using the "square pulse" technique. Changes in the time course and spatial spread of subthreshold electrotonic potentials were measured. If acetylcholine is applied in concentrations which cause slowing or stoppage of the heart beat, the following changes are produced: (a) the length constant (lambda) of the membrane is reduced, (b) the time constant is shortened. The effects are reversible and increase with acetylcholine concentration. The membrane changes caused by acetylcholine dimmish with time. It is concluded that during acetylcholine inhibition, as well as during vagal inhibition, the conductance of the muscle membrane is increased. Appreciable changes in the resting membrane potential need not accompany inhibition.

Entities: Chemical

Keywords: ACETYLCHOLINE/effects; HEART/effect of drugs on

Mesh：

Substances：
Acetylcholine

Year: 1956 PMID： 13357742 PMCID： PMC2147603 DOI： 10.1085/jgp.40.1.135

Source DB: PubMed Journal: J Gen Physiol ISSN： 0022-1295 Impact factor: 4.086

13 in total

6. The effect of changes in extracellular potassium concentration on the intracellular potentials of isolated rabbit atria.

Authors: E M VAUGHAN WILLIAMS
Journal: J Physiol Date: 1959-06-11 Impact factor: 5.182

Changes in membrane characteristics of heart muscle during inhibition.

1. Production of membrane potential changes in the frog's heart by inhibitory nerve impulses.

2. The inhibitory suppression of reflex discharges from motoneurones.

3. Response of single motoneurons to direct stimulation in toad's spinal cord.

4. Cardiac cellular potentials; effect of vagal stimulation and acetylcholine.

5. The effect of inhibitory nerve impulses on a crustacean muscle fibre.

6. Studies on permeability. VIII. Role of acetylcholine metabolism in the genesis of the electrocardiogram.

7. The electrical constants of Purkinje fibres.

8. On the negative inotropic effect in the cat's auricle.

9. Synaptic inhibition in an isolated nerve cell.

10. Vagal and sympathetic effects on the pacemaker fibers in the sinus venosus of the heart.

1. The influence of non-uniformity on the analysis of potassium currents in heart muscle.

2. Electrophysiological properties of tissue cultured heart cells grown in a linear array.

3. [COMPARISON BETWEEN FLOW MEASUREMENTS AND ELECTRIC MEASUREMENTS OF THE MYOCARDIUM].

4. [Sodium exchange in the atrium of the frog heart].

5. [Electrophysiological demonstration of spontaneous liberation of acetylcholine in the auricle of the heart].

6. The effect of changes in extracellular potassium concentration on the intracellular potentials of isolated rabbit atria.

7. Excitation and conduction in the smooth muscle of the isolated taenia coli of the guinea-pig.

8. Ion movement and cardiac fibrillation.

9. Some observations concerning the mode of action of acetylcholine in isolated rabbit atria.

10. Electrical constants of trabecular muscle from mammalian heart.