Binding of wheat-germ agglutinin to glycoconjugates in the salivary glands of reserpinized rats.

Salivary glands from adult rats that had received reserpine for 1, 3 or 7 days and from saline-treated controls were treated with rhodamine-labelled wheat-germ agglutinin conjugates (WGA-TRITC) to localize and characterize the distribution of glycoconjugates. Fluorescent and morphometric analysis of the parotid, submandibular and sublingual glands indicated that each gland responded differently to reserpine treatment. Parotid gland acinar cells and ducts showed no change in pattern or intensity of WGA-TRITC staining after reserpine. Mucous acinar cells of the submandibular gland had increased WGA binding and an accumulation of WGA-positive material in duct lumina after 3-7 days of reserpine. Morphometric analysis showed that the maximal increase in submandibular acinar-cell size occurred after 1 day of reserpine treatment. In sublingual glands, there was no detectable increase in mucous acinar-cell staining, but progressive accumulation of WGA-positive material was seen in duct lumina after 7 days of reserpine. As WGA binds to N-acetyl-glucosamine and N-acetyl-neuraminic acid residues, it may be that the eventual blockage of the duct system is related to increased production and secretion of glycoconjugates that contain these carbohydrates.