Title

Fiber Number and Type Composition in Extensor Digitorum Longus, Soleus, and Diaphragm Muscles with Aging in Fisher 344 Rats

Document Type

Article

Language

eng

Format of Original

9 p.

Publication Date

10-1985

Publisher

Histochemical Society

Source Publication

Journal of Histochemistry and Cytochemistry

Source ISSN

0022-1554

Abstract

Histochemical (M-ATPase) fiber typing was done on extensor digitorum longus, (EDL), soleus (SOL), and diaphragm (DIA) muscles of barrier-reared Fisher 344 rats obtained at four different ages (3, 9, 28, and 30 months) from the colonies of the National Institute of Aging. In the EDL there are no differences in the percent of type I fibers among the four age groups. The percent of type IIa and IIb fibers also showed no difference between the 3 and 30 month age groups. There was no apparent trend for an increase or decrease in the percent of type IIa or IIb fibers between the four age groups. In both the SOL and DIA muscles the percent of type I fibers was greater in the aged than in the young groups. The percent of type IIa fibers was lower in the 30 month group than in the younger groups for both muscles. The percent of type IIb (DIA) and IIc (SOL) fibers did not change between groups. Total fiber number per cross section of muscle showed no change in the EDL over this age range or in the SOL after 9 months of age. These findings bring into question published results that imply that decreasing fiber number and preferential loss of type II (a and b) fibers are typical aging phenomena.

Comments

Journal of Histochemistry and Cytochemistry, Vol. 33, No. 10 (October 1985): 1033-1041. DOI.

Thomas Eddinger was affiliated with the University of Wisconsin - Madison at the time of publication.