Document Detail

Actions of calcium and certain multivalent cations on potassium contracture of guinea-pig's taenia coli.
MedLine Citation:
PMID:  6038017     Owner:  NLM     Status:  MEDLINE    
1. Using a calcium buffer system, the effect of severe calcium lack on the shape of K-contracture of the guinea-pig's taenia coli was studied. Under conditions of calcium lack, the initial phasic response was preferentially affected and it disappeared completely at concentrations below 10(-7)M, while the ensuing tonic response persisted, though considerably diminished in size, even at the concentration of 10(-8)M.2. In calcium-free media, various multivalent cations, which according to Frank (1962) can support the K-contracture of a skeletal twitch muscle fibre in calcium-free solution, augmented the remaining tonic response, but did not restore the phasic response, when it was eliminated in calcium free environment.3. When K-contractures were induced in normal calcium media, these cations produced, in contrast, an abolition of the phasic response together with a partial depression of the tonic phase. They also inhibited a part of the fully developed contracture. The last effect was no longer obtainable in calcium-free media.4. It is concluded that the phasic response and a part of the tonic response of taenia coli depend upon the extracellular calcium for their initiation (and also for maintenance of tension in the case of the latter) and that the rest of the tonic response draws on a store of ;bound' calcium for its evolution.
S Imai; K Takeda
Related Documents :
25318607 - Differential neuroprotective and anti-inflammatory effects of l-type voltage dependent ...
2887417 - Microcirculation and neurotransmitter metabolism in the pathophysiology of brain ischae...
10684727 - A novel model for the in vivo monitoring of uterine microcirculation and intracellular ...
2682207 - Appraisal of the physiological relevance of two hypothesis for the mechanism of calcium...
14599447 - The toxicity of h2o2 on the ionic homeostasis of airway epithelial cells in vitro.
17301497 - Cell volume regulation in the perfused liver of a freshwater air-breathing cat fish cla...
Publication Detail:
Type:  In Vitro; Journal Article    
Journal Detail:
Title:  The Journal of physiology     Volume:  190     ISSN:  0022-3751     ISO Abbreviation:  J. Physiol. (Lond.)     Publication Date:  1967 May 
Date Detail:
Created Date:  1967-10-22     Completed Date:  1967-10-22     Revised Date:  2010-09-13    
Medline Journal Info:
Nlm Unique ID:  0266262     Medline TA:  J Physiol     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  155-69     Citation Subset:  IM    
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Cadmium / pharmacology
Calcium / pharmacology*
Colon / drug effects*
Guinea Pigs
Manganese / pharmacology
Membrane Potentials
Muscle Contraction / drug effects*
Muscle, Smooth / drug effects*
Potassium / pharmacology*
Reg. No./Substance:
7439-96-5/Manganese; 7440-09-7/Potassium; 7440-43-9/Cadmium; 7440-70-2/Calcium

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

Previous Document:  Spatial interaction in human cone vision.
Next Document:  Release of neurohypophysial hormones in vitro.