Lectin histochemistry of the olfactory surface in two teleostean fishes

A histochemical study on carbohydrate sequences in the epithelial surface of the olfactory organs in 2 teleostean species was carried out by means of lectins conjugated with peroxidase. At the same time, the distribution of the 2 kinds of epithelium are found, and the influence of decalcification with HNO3 in the pattern of reactivity to the lectins used were studied. The 2 components which reacted with the lectins were: 1. the apical surface of the olfactory epithelium, which was rich in L-mannose, N-acetyl-glucosamine, or sialic acid residues, and 2. the goblet cells which presented N-acetyl-glucosamine or sialic acid and N-acetyl-galactosamine. In neither site were found residues of L-fucose. The non-olfactory epithelium, where the goblet cells were located, showed signs of proceeding from a metaplasia of the olfactory epithelium. The decalcification in general terms supposed an intensification of the binding of the lectins to the tissues studied, and also the presence of new affinities which were not found without this treatment. In conclusion, the olfactory epithelium of these 2 teleostean fishes showed a rich layer of carbohydrates on its surface that is probably not only secreted by the goblet cells but also by the supporting cells.