Perspectives on carbonic anhydrase

In the years since Larimer and Schmidt-Nielsen published their examination of red blood cell (RBC) carbonic anhydrase (CA) activities as a function of body mass in mammals, our knowledge of CA has expanded dramatically. We are now aware of the diversity of CA isoforms and their implication in a wide array of physiological processes. The catalytic mechanism of CA has been described, and numerous compounds that function as activators or inhibitors of CA activity have been identified. CA is investigated as a diagnostic tumor marker, and CA inhibitors are used or emerging as clinical treatments for diseases as diverse as glaucoma, cancer and obesity. Yet despite the intensity of research effort over the last 50 years and the wealth of information that has accumulated, the questions asked by Larimer and Schmidt-Nielsen remain relevant today — we still have much to learn about the patterns and physiological significance of interspecific differences in CA expression and activity.