LOCALIZATION OF CARBONIC ANHYDRASE IN AVIAN GASTRIC MUCOSA, SHELL GLAND AND BONE BY IMMUNOHISTOCHEMISTRY

Abstract

Antisera to purified avian erythrocyte carbonic anhydrase (CA) were produced in rabbits and the γ-globulin fractions were isolated and purified by ammonium sulfate precipitation and diethylaminoethyl-Sephadex chromatography. The anti-CA immuno-γ-globulins were tested by immunoelectrophoresis and judged to be highly specific for CA. Fluorescein isothiocyanate-conjugated goat antirabbit γ-globulins were used in the indirect fluorescent antibody localization of CA in cryostat sections. Specific fluorescence of CA was observed in gastric mucosal lining cells, shell gland columnar and tubular gland cells, red blood cells, erythroblasts and osteoclasts. Specific fluorescence was absent in the several immunologic controls, including the blocking test. Specific fluorescence was also lacking in tissue constituents which contain no detectable amounts of CA, i.e., muscle, connective tissue, blood vessels and nuclei. A significant finding in this study is the occurrence of cross-reactions between antibodies to red blood cell CA and CA from other tissues, indicating the immunologic similarity of CA from different tissue sources.