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Updated: Aug 10, 2026

Measurement of Smooth Muscle Function in the Isolated Tissue Bath-applications to Pharmacology Research
Published on: January 19, 2015
Regulation of smooth muscle myosin
1Rosenstiel Research Center, Brandeis University, Waltham, MA 02254.
Abstract:
It is well established that light chain phosphorylation is required before a smooth muscle can generate force. The apparent modulation of shortening velocity by phosphorylation during sustained contractions may be accounted for by a mechanical interaction between rapidly cycling phosphorylated crossbridges and slowly or non-cycling dephosphorylated crossbridges. Latchbridges, force-producing dephosphorylated crossbridges, have been proposed to explain why force levels remain high at low levels of phosphorylation. The role of the thin-filament-associated proteins caldesmon and calponin in regulation remains enigmatic, but their inhibitory properties in solution would be consistent with a possible involvement in maintenance of a relaxed state.
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