Christie K N, Thomson C, Xue L, Lucocq J M, Hopwood D
Department of Anatomy, University of Dundee, Scotland, United Kingdom.
J Histochem Cytochem. 1997 Jan;45(1):35-40. doi: 10.1177/002215549704500105.
Carbonic anhydrase (CA) isoenzymes have been widely studied in the gastrointestinal tract, where they mediate membrane transport events and pH regulation. However, the esophagus has generally received scant attention. In an immunohistochemical study confirmed by Western blotting, we have detected for CA isoenzymes (CAI, II, III, and IV) in the epithelium of human esophagus. Isoenzymes I, III, and sometimes IV (< 10%) were present in the cytoplasm of basal cells and II and IV in the cytoplasm and cell surface membranes, respectively, of suprabasal cells (prickle cells). The localization of CAIV to the plasma membranes was confirmed by electron microscopic immunocytochemistry. CA was effectively divided at the basal-suprabasal interface between low-activity CAI and III (basal) and high-activity CAII and IV (suprabasal). Carbonic anhydrase in esophageal epithelial cells may have several functions: elimination of CO2 and metabolites, participation in membrane transport events during active cell growth, and pH regulation as a protective mechanism against acidic gastric reflux.
碳酸酐酶（CA）同工酶在胃肠道中已得到广泛研究，它们在胃肠道中介导膜转运过程和pH调节。然而，食管通常很少受到关注。在一项经蛋白质印迹法证实的免疫组织化学研究中，我们在人食管上皮中检测到了CA同工酶（CAI、II、III和IV）。同工酶I、III以及有时IV（<10%）存在于基底细胞的细胞质中，而II和IV分别存在于基底上层细胞（棘细胞）的细胞质和细胞表面膜中。通过电子显微镜免疫细胞化学证实了CAIV定位于质膜。在基底 - 基底上层界面处，CA被有效地分为低活性的CAI和III（基底）以及高活性的CAII和IV（基底上层）。食管上皮细胞中的碳酸酐酶可能具有多种功能：消除二氧化碳和代谢产物，在活跃细胞生长过程中参与膜转运过程，以及作为针对酸性胃反流的保护机制进行pH调节。
