Carbonic anhydrase III content in various equine muscles

1. In this study, carbonic anhydrase III (CA-III) content in 18 equine muscles was determined by enzyme immunoassay. 2. It was found to differ in several muscles. 3. That in external intercostal muscle, rectus abdominis muscle and splenius muscle from four horses was very high. 4. Although the masseter muscle had only type I fibers, CA-III content was similar to that in mixed-fiber type muscles such as the biceps femoris muscle. 5. It thus appear that equine type I fibers can be further subgrouped.