Copyright ©2005 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Jan 14, 2005; 11(2): 155-163
Published online Jan 14, 2005. doi: 10.3748/wjg.v11.i2.155
Carbonic anhydrases in normal gastrointestinal tract and gastrointestinal tumours
Antti J. Kivelä, Jyrki Kivelä, Juha Saarnio, Seppo Parkkila
Antti J. Kivelä, Department of Anatomy and Cell Biology, University of Oulu, Finland
Antti J. Kivelä, Seppo Parkkila, Institute of Medical Technology, University of Tampere and Tampere University Hospital, Finland
Jyrki Kivelä, Institute of Dentistry, University of Helsinki, Finland
Jyrki Kivelä, Research Institute of Military Medicine, Central Military Hospital, Helsinki, Finland
Juha Saarnio, Department of Surgery, University of Oulu, Finland
Seppo Parkkila, Department of Clinical Chemistry, University of Oulu, Finland
Author contributions: All authors contributed equally to the work.
Supported by the Grants from Sigrid Juselius Foundation, The Academy of Finland (SP), Finnish Cultural Foundation and Finnish Dental Society (JK)
Correspondence to: Antti J. Kivelä, Institute of Medical Technology, University of Tampere, Biokatu 6, FIN-33520 Tampere, Finland.
Telephone: +358-50-3247762 Fax: +358-3-2158597
Received: March 27, 2004
Revised: March 28, 2004
Accepted: May 13, 2004
Published online: January 14, 2005

Carbonic anhydrases (CAs) catalyse the hydration of CO2 to bicarbonate at physiological pH. This chemical interconversion is crucial since HCO3- is the substrate for several biosynthetic reactions. This review is focused on the distribution and role of CA isoenzymes in both normal and pathological gastrointestinal (GI) tract tissues. It has been known for many years that CAs are widely present in the GI tract and play important roles in several physiological functions such as production of saliva, gastric acid, bile, and pancreatic juice as well as in absorption of salt and water in intestine. New information suggests that these enzymes participate in several processes that were not envisioned earlier. Especially, the recent reports on plasma membrane-bound isoenzymes IX and XII have raised considerable interest since they were reported to participate in cancer invasion and spread. They are induced by tumour hypoxia and may also play a role in von Hippel-Lindau (VHL)-mediated carcinogenesis.

Keywords: Gastrointestinal tract, Gastrointestinal tumour, Carbonic anhydrases