Document Detail

Skeletal muscle force and actomyosin ATPase activity reduced by nitric oxide donor.
MedLine Citation:
PMID:  9338443     Owner:  NLM     Status:  MEDLINE    
Nitric oxide (NO) may exert direct effects on actin-myosin cross-bridge cycling by modulating critical thiols on the myosin head. In the present study, the effects of the NO donor sodium nitroprusside (SNP; 100 microM to 10 mM) on mechanical properties and actomyosin adenosinetriphosphatase (ATPase) activity of single permeabilized muscle fibers from the rabbit psoas muscle were determined. The effects of N-ethylmaleimide (NEM; 5-250 microM), a thiol-specific alkylating reagent, on mechanical properties of single fibers were also evaluated. Both NEM (>/=25 microM) and SNP (>/=1 mM) significantly inhibited isometric force and actomyosin ATPase activity. The unloaded shortening velocity of SNP-treated single fibers was decreased, but to a lesser extent, suggesting that SNP effects on isometric force and actomyosin ATPase were largely due to decreased cross-bridge recruitment. The calcium sensitivity of SNP-treated single fibers was also decreased. The effects of SNP, but not NEM, on force and actomyosin ATPase activity were reversed by treatment with 10 mM DL-dithiothreitol, a thiol-reducing agent. We conclude that the NO donor SNP inhibits contractile function caused by reversible oxidation of contractile protein thiols.
W J Perkins; Y S Han; G C Sieck
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Publication Detail:
Type:  In Vitro; Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Journal of applied physiology (Bethesda, Md. : 1985)     Volume:  83     ISSN:  8750-7587     ISO Abbreviation:  J. Appl. Physiol.     Publication Date:  1997 Oct 
Date Detail:
Created Date:  1997-11-26     Completed Date:  1997-11-26     Revised Date:  2013-09-26    
Medline Journal Info:
Nlm Unique ID:  8502536     Medline TA:  J Appl Physiol (1985)     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  1326-32     Citation Subset:  IM    
Department of Anesthesiology, Mayo Clinic and Foundation, Rochester, Minnesota 55905, USA.
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MeSH Terms
Alkylating Agents / pharmacology
Dithiothreitol / pharmacology
Ethylmaleimide / pharmacology
Isometric Contraction / drug effects,  physiology
Muscle Contraction / physiology
Muscle Fibers, Skeletal / drug effects,  physiology
Muscle, Skeletal / drug effects,  enzymology*,  physiology*
Myosins / metabolism*
Nitric Oxide / physiology*
Nitroprusside / pharmacology*
Psoas Muscles / cytology,  drug effects,  physiology
Respiratory System Agents / pharmacology
Sulfhydryl Compounds / metabolism
Grant Support
Reg. No./Substance:
0/Alkylating Agents; 0/Respiratory System Agents; 0/Sulfhydryl Compounds; 10102-43-9/Nitric Oxide; 128-53-0/Ethylmaleimide; 15078-28-1/Nitroprusside; 3483-12-3/Dithiothreitol; EC

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