Lectinhistochemical observations on the bronchial glands and the goblet cells of the airway epithelium of marine diving mammals.

Carbohydrate components were investigated in the bronchial glands and goblet cells of two species of seals with different diving habits (Weddell seal, Crabeater seal). Bouin-fixed tissue was incubated with various fluorescein-iso-thiocyanate-conjugated lectins (WGA, RCA I, PNA, PHA I, HPA, GSA I, DBA, Con A, LFA, SBA, UEA I), additionally PAS- and HID-reactions as well as Alcian Blue stains were applied. The two species differ in respect of their carbohydrate histochemistry, e.g., the PAS reaction gives only a faint stain at the apical membrane in the bronchial glands of the Weddell seal, whereas in the Crabeater seal several cells give a positive reaction in the entire cytoplasm; or RCA I has only few binding sites at the apical membranes of the bronchial glandular cells of the Weddell seal whereas many cells of Crabeater bronchial glands react strongly positive. It is concluded that the secretory products of the bronchial glands of the long- and deep-diving Weddell seal are relatively poor in mucins, which is in contrast to other mammals studied so far.