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.
Department of Physiology, Medical College of Virginia, Virginia Commonwealth University, Richmond 23298-0551.
H
H
Meng
T B
TB
Bentley
R N
RN
Pittman
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