An enzyme histochemical study of large muscle fibres in the neonatal mouse.
Small clusters of extra large muscle fibres were identified in hindlimb muscles of neonatal mice (strain C57BL/10ScSn). At two days of age they had a significantly greater cross-sectional area than their normal counterparts (P less than 0.01). Fibre typing methods (NADH-tetrazolium reductase, ATPase and phosphorylase) classified them as 2A fast oxidative glycolytic (FOG fibres). The activity of NADH-tetrazolium reductase and the lysosomal enzymes beta-glucuronidase, acid phosphatase and dipeptidyl peptidase II were all elevated in the large fibres. Microsomal aminopeptidase (mAPP), a membrane-bound enzyme, also showed increased activity. The fibres are probably the mouse equivalent of the Wohlfart B fibres of the human fetus, with which comparison is made.
Christie
K N
KN
Department of Anatomy and Physiology, The University, Dundee, Scotland.
Stewart
R J
RJ
Bacciocchi
G
G
D000375:Aging / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn / Q000033:anatomy & histology / Q000378:metabolism*; D010450:Endopeptidases / Q000378:metabolism; D005260:Female; D006614:Hindlimb / Q000201:enzymology; D006867:Hydrolases / Q000378:metabolism; D007124:Immunoenzyme Techniques; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL / Q000033:anatomy & histology / Q000378:metabolism; D009132:Muscles / Q000033:anatomy & histology / Q000201:enzymology*
D006867:Hydrolases; D010450:Endopeptidases