Title :
Mechanism of Ca/sup ++/ release from the myocyte sarcoplasmic reticulum: a model study
Author :
Glukhovsky, Arkady ; Adam, Dan ; Amitzur, Giora ; Sideman, Samuel
Author_Institution :
Julius Silver Inst. of Biomed. Eng., Technion-Israel Inst. of Technol., Haifa, Israel
Abstract :
The mechanism of Ca/sup ++/ release from the cardiac sarcoplasmic reticulum (SR) is still uncertain. It is assumed here that the release of Ca/sup ++/ from the SR is mainly regulated by the kinetics of Ca/sup ++/ channels within the SR membrane. These kinetics are controlled, under physiological conditions, by changes in the concentration of free Ca/sup ++/ near the openings of Ca/sup ++/ channels, and are affected by Ca/sup ++/ competitors, e.g. ryanodine. The study describes this control mechanism by a combination of positive and negative control loops, associated with two types of Ca/sup ++/ binding sites located on the SR membrane: (1) activating sites with low affinity to Ca/sup ++/ and high binding rare, and (2) inactivating sites with high affinity but low binding rate. This model successfully describes the process of Ca/sup ++/ release from the SR. The ryanodine intervention supports the hypothesis of the control mechanism described by the model.<>
Keywords :
bioelectric phenomena; biomembrane transport; calcium; muscle; physiological models; Ca; Ca/sup 2+/ channels kinetics; Ca/sup 2+/ release mechanism; activating sites; binding sites; control mechanism; model study; myocyte sarcoplasmic reticulum; negative control loops; physiological conditions; positive control loops; ryanodine; Biomedical engineering; Biomembranes; Calcium; Extracellular; Feedback; Kinetic theory; Muscles; Open loop systems; Silver; Strontium;
Conference_Titel :
Computers in Cardiology 1994
Conference_Location :
Bethesda, MD, USA
Print_ISBN :
0-8186-6570-X
DOI :
10.1109/CIC.1994.470112
