Faculty Collaboration Database

Mechanical properties of skinned single fibers of identified types from rat diaphragm. Am J Physiol 1987 Aug;253(2 Pt 1):C210-8

Date

08/01/1987

Pubmed ID

3303962

DOI

10.1152/ajpcell.1987.253.2.C210

Scopus ID

2-s2.0-0023280831 (requires institutional sign-in at Scopus site)   76 Citations

Abstract

Maximum isometric tension (Po), maximum velocity of shortening (Vmax), and tension-pCa (i.e., -log[Ca2+]) relationships were determined in single skinned fibers from rat diaphragm. Histochemistry (myosin-ATPase) and sodium dodecyl sulfate (SDS) gel electrophoresis were performed on these same fibers to determine fiber type and protein composition. Physiologically fast fibers were found to have larger cross-sectional areas (CSA) and produced more tension per CSA and were less sensitive to [Ca2+] than physiologically slow fibers. Fast fibers were typed histochemically as type II and contained myosin heavy chains (MHC) and light chains (LC) of the fast type, whereas the slow fibers contained slow MHC and LC. There were also corresponding differences in the regulatory protein composition of these two fiber types. The histochemical sections confirmed a significant fiber size difference between the type IIa and IIb fibers. When fiber size was used to separate the fast fibers into two groups, type IIb fibers were found to have significantly greater Vmax and tension per CSA than the type IIa fibers. Although there were no noticeable differences in MHC composition between the type IIa and IIb fibers, there were some differences in the myosin LC and regulatory protein content.

Author List

Eddinger TJ, Moss RL

Author

Thomas Eddinger PhD Bioological Sciences in the Biology department at Marquette University

MESH terms used to index this publication - Major topics in bold

Animals
Biomechanical Phenomena
Diaphragm
Electrophoresis, Polyacrylamide Gel
Histocytochemistry
Histological Techniques
Muscle Contraction
Muscle Proteins
Myosins
Rats
Rats, Inbred Strains