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The sarcoplasmic reticulum and the control of muscle contraction
Author(s) -
FranziniArmstrong Clara
Publication year - 1999
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.13.9002.s266
Subject(s) - endoplasmic reticulum , contraction (grammar) , muscle contraction , chemistry , biophysics , medicine , biology , biochemistry
Activation of muscle contraction is a rapid event that is initiated by electrical activity in the surface membrane and transverse (T) tubules. This is followed by release of calcium from the inner membrane system, the sarcoplasmic reticulum (SR). Using electron microscopy (EM), K. R. Porter and his laboratory defined the SR, the unique junctions between SR and T tubules, and the continuity between T tubules and surface membrane. Current research in this area centers on the interaction between T tubules and SR. This is mediated by 2 well‐identified calcium channels: the dihydropyridine receptors (DHPRs) that act as voltage sensors in the T tubules, and the ryanodine receptors (RyRs) or calcium release channels of the SR. The relative positions of these 2 molecules differ significantly in skeletal and cardiac muscle, and this correlates well with known functional differences in the control of contraction. Molecular biology experiments combined with EM indicate that DHPRs are linked to RyRs in skeletal but probably not in cardiac muscle.—Franzini‐Armstrong, C. The sarcoplasmic reticulum and the control of muscle contraction. FASEB J. 13 (Suppl.), S266‐S270 (1999)