Publication Date:
1983-03-04
Description:
Calcium ions activate muscle contraction. The mechanism depends on the calcium sensitivity of the proteins that regulate contraction. Evidence is presented for the reverse phenomenon, where contraction modulates calcium sensitivity. Increasing the force level increased calcium sensitivity in intact fibers showing that the relation between force and calcium is not unique. A particular calcium concentration can maintain a higher force level than it can create. The results were confirmed in skinned fiber experiments. Transient reduction of the force led to a transient reduction in calcium binding, suggesting a simple mechanism for the hysteresis.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Ridgway, E B -- Gordon, A M -- Martyn, D A -- NS 08384/NS/NINDS NIH HHS/ -- NS 10919/NS/NINDS NIH HHS/ -- New York, N.Y. -- Science. 1983 Mar 4;219(4588):1075-7.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6823567" target="_blank"〉PubMed〈/a〉
Keywords:
Aequorin
;
Animals
;
Calcium/metabolism/*physiology
;
Dose-Response Relationship, Drug
;
*Muscle Contraction
;
Protein Binding
;
Thoracica
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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