Myoglobin content of hamster skeletal muscles.
Myoglobin (Mb) may facilitate O2 diffusion in muscle tissue, yet models of O2 transport are often simplified by ignoring the role of Mb. A recent analysis of O2 transport in hamster retractor muscle revealed a large discrepancy between the observed O2 diffusion from arterioles and that predicted by a mathematical model that did not include Mb. To establish whether this simplification was justified, we measured Mb content ([Mb]) in three hamster muscles that vary markedly in histochemical fiber type composition. [Mb] was determined spectrophotometrically using freshly excised tissues from hamsters of different ages (5-34 wk). [Mb] increased rapidly up to 15 wk of age and then rose more slowly. [Mb] in hamster muscles paralleled oxidative capacity. Our measurements of rat and dog muscles also show that [Mb] varies greatly among species and among muscles of a given species. The results indicate that in the hamster the variability in [Mb] with age and muscle should be taken into account when the potential role of Mb in studies on O2 transport is interpreted.
Meng
H
H
Department of Physiology, Medical College of Virginia, Virginia Commonwealth University, Richmond 23298-0551.
Bentley
T B
TB
Pittman
R N
RN
D000375:Aging / Q000502:physiology; D000818:Animals; D006224:Cricetinae; D003574:Cytochrome c Group / Q000378:metabolism; D004285:Dogs; D008297:Male; D008647:Mesocricetus; D008931:Mitochondria, Muscle / Q000201:enzymology; D009132:Muscles / Q000201:enzymology / Q000378:metabolism*; D009211:Myoglobin / Q000378:metabolism*; D010101:Oxygen Consumption / Q000502:physiology; D051381:Rats; D013045:Species Specificity
D003574:Cytochrome c Group; D009211:Myoglobin