Document Detail


Comparison of the biphasic excitatory junction potential with membrane responses to adenosine triphosphate and noradrenaline in the rat anococcygeus muscle.
MedLine Citation:
PMID:  6509261     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The effects of field stimulation and ionophoretic application of adenosine triphosphate (ATP) and noradrenaline were studied in the rat anococcygeus by means of an intracellular microelectrode. Field stimulation at room temperature produced three types of electrical membrane response: (a) a 'fast' excitatory junction potential (e.j.p.) which had a latency of less than 100 ms and a time to peak of 300 ms; (b) a 'slow' e.j.p. which had a latency of several hundred ms and a time to peak of 1-2 s, and (c) an inhibitory junction potential (i.j.p.) which had a time to peak of about 1.5 s. All three responses were blocked by tetrodotoxin. The ionophoretic application of ATP produced both monophasic and biphasic depolarizations; these responses had a latency of less than 30 ms and a time to peak of 150-300 ms. In contrast, ionophoretically-applied noradrenaline produced a depolarization which had a mean latency of 471 ms and a time to peak of 861 ms. The 'slow' e.j.p. and the noradrenaline-induced depolarization were blocked by prazosin whereas the 'fast' e.j.p. and the ATP responses were resistant to this antagonist and also to atropine. These results are further evidence that the 'fast' e.j.p. in some smooth muscle tissues is mediated by ATP.
Authors:
N G Byrne; W A Large
Publication Detail:
Type:  Comparative Study; In Vitro; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  British journal of pharmacology     Volume:  83     ISSN:  0007-1188     ISO Abbreviation:  Br. J. Pharmacol.     Publication Date:  1984 Nov 
Date Detail:
Created Date:  1985-01-31     Completed Date:  1985-01-31     Revised Date:  2009-11-18    
Medline Journal Info:
Nlm Unique ID:  7502536     Medline TA:  Br J Pharmacol     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  751-8     Citation Subset:  IM    
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MeSH Terms
Descriptor/Qualifier:
Adenosine Triphosphate / pharmacology*
Animals
Electric Stimulation
Evoked Potentials / drug effects
Membrane Potentials / drug effects
Membranes / metabolism
Muscles / drug effects*
Neuromuscular Junction / drug effects*
Norepinephrine / pharmacology*
Rats
Tetrodotoxin / pharmacology
Yohimbine / pharmacology
Chemical
Reg. No./Substance:
146-48-5/Yohimbine; 4368-28-9/Tetrodotoxin; 51-41-2/Norepinephrine; 56-65-5/Adenosine Triphosphate
Comments/Corrections

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