Lectin histochemistry of developing submandibular glands of fetal Syrian golden hamsters

Lectin binding was studied in the developing submandibular glands of fetal Syrian golden hamsters (Mesocricetus auratus) from gestational day 12 to 16 (the day of birth). The fetuses were fixed, embedded in paraffin, sectioned and stained with nine lectin-horseradish peroxidase conjugates: concanavalin A (Con A), wheat germ agglutinin (WGA), Dolichos biflorus agglutinin (DBA), Helix pomatia agglutinin (HPA), Maclura pomifera agglutinin (MPA). Griffonia simplicifolia agglutinin I-B4 (GSA I-B4), peanut agglutinin (PNA). Ulex europeus agglutinin I (UEA I) and Limulus polyphemus agglutinin (LPA). The developing glands showed dramatic morphological alterations on a daily basis, accompanied by progressive changes in lectin staining. On day 12 the primitive gland showed only trace lectin staining with WGA, HPA, MPA, PNA and UEA I, but by day 13, strong staining with these lectins, as well as with DBA, was seen at the ductal lumenal surface, after the formation of the ductal lumens. Secretory granules first appeared in cells of the primitive acini on day 14: the secretion products were stained strongly with WGA. DBA, HPA, MPA, PNA and UEA I. On day 15, the secretion products were also stained moderately with GSA I-B4. Secretory differentiation was further developed on day 16, but the staining intensity of the mucins with the different lectins varied among the secretory cells. LPA failed to stain any part of the gland throughout the observation period, and Con A stained only glycogen.