Regional differences in myosin heavy chain isoforms and enzyme activities of the rat diaphragm.
Myosin heavy chain isoforms and enzyme activities were compared between the costal and crural regions of the rat diaphragm. The percentage of heavy chain (HC) IIb in the crural region of the diaphragm was significantly (P less than 0.05) higher than that in the costal region (mean 7.3 vs. 3.0%), and the percentage of HCI was significantly lower in the crural than in the costal diaphragm (22.7 vs. 27.9%). The distributions of HCIIa and HCIId were relatively homogeneous in both regions. Succinate dehydrogenase activity in the costal diaphragm was 21% greater (P less than 0.01) than in the crural diaphragm. In contrast, there was no significant difference in the activity of phosphofructokinase in the crural and costal diaphragms. These results demonstrate that a difference in myosin heavy chain isoforms and oxidative capacity exists between the costal and crural regions of the rat diaphragm.
Sugiura
T
T
Laboratory of Biomechanics and Physiology, College of General Education, Yamaguchi University, Japan.
Morita
S
S
Morimoto
A
A
Murakami
N
N
D000818:Animals; D003964:Diaphragm / Q000378:metabolism; D004586:Electrophoresis; D007536:Isomerism; D008297:Male; D009218:Myosins / Q000378:metabolism*; D010732:Phosphofructokinase-1 / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012132:Respiratory Muscles / Q000378:metabolism*; D013385:Succinate Dehydrogenase / Q000378:metabolism
D013385:Succinate Dehydrogenase; D010732:Phosphofructokinase-1; D009218:Myosins