Demonstration of sugar residues in the ultimobranchial tubule and thyroid C-cells of the rat using peroxidase labelled lectins.

The distribution of various sugars, that contribute to the composition of the carbohydrate components of the glycoprotein in the ultimobranchial tubule and the thyroid C-cells has been studied, using eight peroxidase-labelled lectins (Dolichos biblorus, Glycine max, Bauhinia purpurea, Helix pomatia, Arachis hipogaea, Ulex europaeus I, Limax flavus and Sophora japonica). The results obtained seem to show that there are receptors for Dolichos biflorus, Glycine max, Bauhinia purpurea, Helix pomatia, Arachis hipogaea, Ulex europaeus I and Limax flavus in the ultimobranchial tubule, suggesting the existence of N-acetylgalactosamine, galactose, L-fucose and sialic acid. However, the C-cells show only a positive reaction with Ulex europaeus I indicating the existence of fucosyl residues in those cells. All these findings support the contention that the ultimobranchial body might contribute decisively not only to the formation of C-cells but also, partially, to the constitution of certain follicular cells.