Carbonic anhydrase inhibition affects contraction of directly stimulated rat soleus

We have studied the contractile parameters of directly stimulated isolated rat soleus muscles incubated in media containing the carbonic anhydrase inhibitors chlorzolamide (5.10(-4)M) or cyanate (10(-2)M). Both inhibitors caused a decrease in isometric twitch and tetanic (5s) tensions and an increase in muscle relaxation time. It is speculated that among the three types of skeletal muscle carbonic anhydrase it may be the enzyme associated with the sarcoplasmatic reticulum whose inhibition caused the observed changes in contractile parameters.