TY - JOUR
T1 - The maximal velocity of vascular smooth muscle shortening is independent of the expression of calponin
AU - Facemire, Carie
AU - Brozovich, Frank V.
AU - Jin, Jian Ping
N1 - Funding Information:
We wish to thank Qi-Quan Huang, Wenhua Chen, Ozgur Ogut, Albert Rhee, Sarah MacFarland and Christopher Richards for their technical assistance and comments on the manuscript. The work was supported by an AHA GIA and a March of Dimes Foundation grant (JPJ) and an NIH grant HL44181 (FVB).
PY - 2000
Y1 - 2000
N2 - In smooth muscle, the phosphorylation/dephosphorylation of the 20-kDa regulatory light chain of myosin (MLC20) is known to regulate actomyosin interaction and force. However, a thin filament based regulatory system for actomyosin interaction has been suggested to exist in parallel to MLC20 phosphorylation. Calponin is a thin filament associated protein that in vitro inhibits actomyosin interaction, and has been suggested to reduce maximal shortening velocity (υ(max)), Using antibodies to h1- and h2-calponin, we demonstrated that calponin was present in smooth muscle from Sprague Dawley (SD) rats, while calponin was not detectable in the smooth muscle from Wistar Kyoto (WKY) rats. V(max) determined from the force vs. velocity relationship at maximal Ca2+ activation was not different for either the aorta or the portal vein of SD vs. WKY rats. These results suggest that physiological levels of calponin do not contribute to a thin filament-based secondary regulation to inhibit smooth muscle contraction.
AB - In smooth muscle, the phosphorylation/dephosphorylation of the 20-kDa regulatory light chain of myosin (MLC20) is known to regulate actomyosin interaction and force. However, a thin filament based regulatory system for actomyosin interaction has been suggested to exist in parallel to MLC20 phosphorylation. Calponin is a thin filament associated protein that in vitro inhibits actomyosin interaction, and has been suggested to reduce maximal shortening velocity (υ(max)), Using antibodies to h1- and h2-calponin, we demonstrated that calponin was present in smooth muscle from Sprague Dawley (SD) rats, while calponin was not detectable in the smooth muscle from Wistar Kyoto (WKY) rats. V(max) determined from the force vs. velocity relationship at maximal Ca2+ activation was not different for either the aorta or the portal vein of SD vs. WKY rats. These results suggest that physiological levels of calponin do not contribute to a thin filament-based secondary regulation to inhibit smooth muscle contraction.
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U2 - 10.1023/A:1005680614296
DO - 10.1023/A:1005680614296
M3 - Article
C2 - 11032347
AN - SCOPUS:0033798958
SN - 0142-4319
VL - 21
SP - 367
EP - 373
JO - Journal of Muscle Research and Cell Motility
JF - Journal of Muscle Research and Cell Motility
IS - 4
ER -