Carbonic anhydrase inhibition and calcium transients in soleus fibers.
We simultaneously measured cytoplasmic Ca2+ transients using Fura-2 and isometric force in rat soleus fiber bundles. In the presence of the carbonic anhydrase inhibitor, chlorzolamide, we observed a decreased amplitude and retarded decay of the Ca2+ signal. This corresponded with a decreased isometric force and a retarded muscle relaxation. We conclude that muscle carbonic anhydrase participates in excitation-contraction coupling, possibly by rapidly providing protons that are exchanged for Ca2+ across the sarcoplasmic reticulum membrane.
Wetzel
P
P
Zentrum Physiologie, Medizinische Hochschule Hannover, FRG.
Liebner
T
T
Gros
G
G
D000086:Acetazolamide / Q000494:pharmacology*; D000138:Acidosis / Q000378:metabolism; D000818:Animals; D001692:Biological Transport; D002118:Calcium / Q000378:metabolism*; D002257:Carbonic Anhydrase Inhibitors / Q000494:pharmacology*; D002256:Carbonic Anhydrases / Q000378:metabolism; D005260:Female; D007527:Isoenzymes / Q000037:antagonists & inhibitors; D007700:Kinetics; D009119:Muscle Contraction / Q000187:drug effects; D009132:Muscles / Q000187:drug effects / Q000201:enzymology*; D051381:Rats; D011919:Rats, Inbred Strains; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism; D012519:Sarcoplasmic Reticulum / Q000187:drug effects / Q000201:enzymology; D013830:Thiadiazoles / Q000494:pharmacology*; D014157:Transcription Factors / Q000235:genetics*
D002257:Carbonic Anhydrase Inhibitors; D007527:Isoenzymes; D012097:Repressor Proteins; D013830:Thiadiazoles; D014157:Transcription Factors; C000471:chlorzolamide; D002256:Carbonic Anhydrases; D000086:Acetazolamide; D002118:Calcium