Chronic stimulation-induced effects point to a coordinated expression of carbonic anhydrase III and slow myosin heavy chain in skeletal muscle.
Chronic low-frequency stimulation of rat fast-twitch muscle induces 3.7-fold elevations in cytochrome c oxidase activity, but remains without effect on carbonic anhydrase III (CAIII) mRNA and protein. This is in contrast with the situation in the rabbit where chronic stimulation elicits more than 10-fold elevations in CAIII activity and mRNA content which coincide with an enhanced expression of the slow myosin heavy chain (HCI). Since chronic stimulation of rat muscle does not enhance the expression of HCI, we conclude that CAIII is expressed in parallel with HCI and, therefore, is present only in type I and C fibers.
Jeffery
S
S
Department of Child Health, St. George's Hospital Medical School, London, UK.
Kelly
C D
CD
Carter
N
N
Kaufmann
M
M
Termin
A
A
Pette
D
D
D000818:Animals; D002256:Carbonic Anhydrases / Q000096:biosynthesis / Q000235:genetics*; D015342:DNA Probes; D003576:Electron Transport Complex IV / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D008297:Male; D009132:Muscles / Q000201:enzymology / Q000378:metabolism*; D009218:Myosins / Q000096:biosynthesis / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains
D015342:DNA Probes; D012333:RNA, Messenger; D003576:Electron Transport Complex IV; D009218:Myosins; D002256:Carbonic Anhydrases