Hamster nasal glands: their structure, sialic acid content, and vulnerability to actinomycin D

This study examines the structure of mucosal glands in the walls of the hamster maxillary recess, compares the histochemical appearance of nasal glands to their sialic acid content, and determines the vulnerability of nasal glands to actinomycin toxicity. Observations were made on plastic-embedded tissue with light and transmission electron microscopes. Determinations of total sialic acid in mucosal samples were conducted with thiobarbituric acid. Experimental hamsters were administered 0.2 micrograms of actinomycin D (IP)/gm body weight/day for five days. Types of granules present in the later nasal gland (LNG) and glands of the maxillary recess (MRGs) include: 2.0 micrometers lightly basophilic, lightly electron-dense granules and 1.5 micrometers strongly basophilic, electron-dense granules in the same acinar cell type in both the LNG and MRGs; 1.5 micrometers metachromatic granules in some acinar cells of the LNG; 1.0 micrometer moderately electron-dense granules in cells of MRG ducts; and 0.7 micrometers electron-dense granules in cells of LNG intercalated ducts. Acid glycoproteins, demonstrable by histochemistry, are present in the LNG but not in the MRGs. However, the total sialic acid content of tissues from MRG tissue is greater than that of other tissues measured. A minor number of LNG acini, those with metachromatic granules, have branching basal cytoplasmic projections. Many dark cells are present in striated ducts of the LNG. Histological alteration due to actinomycin-D toxicity, conspicuous in parotid salivary parenchyma, is greater in MRG than in LNG tissue.