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Enhancement by carbachol of transmitter release from motor nerve terminals.
- Source :
-
Proceedings of the National Academy of Sciences of the United States of America [Proc Natl Acad Sci U S A] 1974 Apr; Vol. 71 (4), pp. 1489-92. - Publication Year :
- 1974
-
Abstract
- In the endplates of rat phrenic nerve-diaphragm, application of the acetylcholine-like compound, carbachol, causes a marked increase in transmitter release, as measured electrophysiologically using miniature endplate potential frequency. Washing out of carbachol reverses the increase in frequency. The ability of carbachol to increase transmitter release is greatly enhanced by perfusion of the preparation with Ringer solution containing elevated K(+). At concentrations of carbachol greater than 30 muM, the onset of the postjunctional blocking action of carbachol is too rapid and obscures the increase in miniature potential frequency. The rate of increase in transmitter release is dependent on the concentration of carbachol applied and can be antagonized by d-tubocurarine (10-60 nM) and other blocking compounds. These findings, in contrast to previous reports, indicate that cholinergic nerve endings, like adrenergic nerve endings, respond to applied acetylcholine-like drugs with measurable increases in transmitter output.
- Subjects :
- Acetylcholine metabolism
Animals
Dose-Response Relationship, Drug
In Vitro Techniques
Male
Neuromuscular Junction metabolism
Neurosecretion drug effects
Osmolar Concentration
Parasympathetic Nervous System drug effects
Phrenic Nerve drug effects
Potassium pharmacology
Rats
Stimulation, Chemical
Action Potentials drug effects
Carbachol pharmacology
Motor Neurons drug effects
Nerve Endings drug effects
Synaptic Transmission drug effects
Subjects
Details
- Language :
- English
- ISSN :
- 0027-8424
- Volume :
- 71
- Issue :
- 4
- Database :
- MEDLINE
- Journal :
- Proceedings of the National Academy of Sciences of the United States of America
- Publication Type :
- Academic Journal
- Accession number :
- 4364541
- Full Text :
- https://doi.org/10.1073/pnas.71.4.1489