Document Detail


Effects of palytoxin on isolated intestinal and vascular smooth muscles.
MedLine Citation:
PMID:  1021604     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Palytoxin (PTX), the most potent marine toxin isolated from the Zoanthid, Palythoa tuberculosa, was studied to determine the effect on isolated smooth muscles. In guinea pig taenia coli PTX at above 3 X 10(-10) g/ml caused a contraction which slowly subsided under isotonic recording. Under isometric recording PTX at above 1 X 10(-10) g/ml caused a contraction which depended on the spontaneous activity. The PTX-induced contraction was not affected by atropine, tripelenmamine or tetrodotoxin but was inhibited by 5 mM Mg, norephinrphrine, isoprenaline or papaverine. PTX at above 1 X 10(-9) g/ml induced an increase in spike frequency and a slight depolarization accompanied with a contraction when measured using a sucrose gap method. In some cases the spike generation was almost abolished after a long exposure to higher dose of PTX and the developed tension gradually decreased. Under isometric recording PTX caused a sustained contraction in rabbit aorta, dog mesenteric and coronary arteries at above 1 X 10(-10) and 1 X 10(-11) g/ml, respectively, in a dose-dependent manner. The coronary artery was most sensitive among the preparation used. PTX-induced contraction in aorta was irreversible, was not influenced by phentolamine but diminished with 5 mM Mg and disappeared in a D-600 or Ca-free medium. PTX is thus an extremely potent and direct stimulant which acts on smooth muscles.
Authors:
K Ito; H Karaki; Y Ishida; N Urakawa; T Deguchi
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Publication Detail:
Type:  In Vitro; Journal Article    
Journal Detail:
Title:  Japanese journal of pharmacology     Volume:  26     ISSN:  0021-5198     ISO Abbreviation:  Jpn. J. Pharmacol.     Publication Date:  1976 Dec 
Date Detail:
Created Date:  1977-05-12     Completed Date:  1977-05-12     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  2983305R     Medline TA:  Jpn J Pharmacol     Country:  JAPAN    
Other Details:
Languages:  eng     Pagination:  683-92     Citation Subset:  IM    
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MeSH Terms
Descriptor/Qualifier:
Acrylamides / pharmacology*
Animals
Aorta, Thoracic / drug effects
Colon / drug effects
Coronary Vessels / drug effects
Dogs
Female
Guinea Pigs
Ileum / drug effects
Male
Marine Toxins / pharmacology*
Membrane Potentials / drug effects
Mesenteric Arteries / drug effects
Muscle Contraction / drug effects*
Muscle, Smooth / drug effects*
Rabbits
Chemical
Reg. No./Substance:
0/Acrylamides; 0/Marine Toxins

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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