Histochemical studies on irradiated and obstructive human submandibular glands. Protein distribution and lectin-binding in the degenerative glands.

Immunohistochemical protein distribution of alpha-amylase (Am), lysozyme (Ly), cytokeratinin (CK), S-100 protein (S-100) and secretory component (SC), and lectin-binding (SBA and UEA-I) profiles were studied in 10 obstructive and 20 irradiated human submandibular glands which were surgically extirpated. Degenerative intensity of the glands was graded as I, II and III based on the order of severity. All proteins generally existed in serous acinic cells of the intact glands. The proteins immunoreactivities became weak even in mildly inflamed glands (grade I), and nearly disappeared from the moderately damaged glands (grade II). Duct cells had clear CK and some cells reacted with the anti-SC antibody, but other proteins were not observed on the ducts. Mucous cells possessed none of the proteins, and their lectin-binding was only traceable in some glands. Compared with immunoreactivities in the proteins, lectin-binding profiles were different. SBA and UEA-I bound somewhat similarly to both acinic and duct cells, and the binding was hardly affected even by severe degeneration (grade III). Between obstructive and irradiated glands, no obvious difference was observed in either protein distribution or lectin-binding. From the above, it seems that some proteins are more affective to the degeneration and that lectin-binding sugar residues are non-affective against the degenerative changes of the tissues.     

Pancreatic duct glands. II. Lectin binding affinities of ductular epithelium,ductular glands,and Brunner glands

Summary Secretory epithelia and ductular glands were studied in main pancreatic ducts of guinea pig, rabbit, rat, and man. Brunner glands were studied for comparison. Semithin sections from Epon-embedded tissues were etched with sodium methylate and incubated with horseradish peroxidase-conjugated lectins. Columnar cells in the epithelium of pancreatic ducts are endowed with well-developed microvillar borders. These apical regions strongly stain with Lotus A-, wheat germ-, and Ricinus I-lectins. Basolateral plasma membranes bind Ricinus I-, Ulex europaeus I-, and wheat germ-lectins. Cytosomes in the supranuclear regions of epithelial cells are interpreted as secretory granules. These droplets are marked by wheat germ-lectin and to a lesser degree by Ricinus I- and Ulex europaeus I-lectins. Ductular glands of the main pancreatic ducts contain secretions that bind Helix-, wheat germ-, and Ulex europaeus I-lectins. Their apical and basolateral cell membranes deeply stain with wheat germ- and Ulex europaeus I-lectins. Secretions of Brunner glands bind Ricinus I-, Ulex europaeus I-, Helix-, and wheat germ lectins. Their apical and basolateral cell membranes stain with Ricinus I- and wheat germ-lectins.-Species differences in lectin-binding affinities of complex carbohydrates were observed and are described.Part of these results has been presented as a poster during the 4th Symposium on Lectins in Cell Biology and Medicine June 25, 1983, Cologne, Federal Republic of Germany     

Phosphatidylinositol-hydrolysing enzymes in blowfly salivary glands.

The salivary glands of adult blowflies (Calliphora erythrocephala) contain enzymes that hydrolyse phosphatidylinositol, predominantly by a Ca2+-independent deacylation, though a Ca2+-dependent phosphodiesterase (phospholipase C) activity could be detected. The deacylating enzymes could also hydrolyse phosphatidylcholine and phosphatidylethanolamine, and were secreted in the saliva. Homogenization of salivary glands prelabelled with [3H]inositol resulted in a rapid deacylation of the endogenous 3H-labelled phosphatidylinositol; this hydrolysis was unaffected by addition of 5-hydroxytryptamine to the homogenate.     

Phosphatases in the lingual glands of man and dog.

Phosphatase activity was demonstrated in the lingual glands of man and dog. Especially the ducts of the glandular elements of the dog exhibited a peculiar and rather perplexing pattern of activity which does not seem to fit in with any of the prevailing concepts of the function of the duct system. The secretory capillaries (Sekretionscapillaren) in many of the serous acini of the human lingual glands have demonstrated phosphatase activity with all the 17 substrates used. The significance of these phosphatases, expecially ATPase, in the active transport across biological unit membranes has been discussed.     

Tissue-specific expression in the salivary glands of transgenic mice.

Using a DNA construct, named Lama, derived from the murine parotid secretory protein (PSP) gene, we have obtained salivary gland specific gene expression in transgenic mice. Lama is a PSP minigene and allows analysis of the PSP gene 5' regulatory region by transgenesis. We show here that the regulatory region included in Lama with 4.6 kb of 5' flanking sequence is sufficient to direct expression specifically to the salivary glands. The expression level in the parotid gland is only about one percent of the PSP mRNA level, while that of the sublingual gland is near the PSP mRNA level. This suggests significant differences in the PSP gene regulation in the two glands. In addition, Lama is a secretory expression vector in which cDNAs or genomic fragments can be inserted. We demonstrate that the Lama construct can direct the expression of a heterologous cDNA encoding the C-terminal peptide of human factor VIII to salivary glands and that the corresponding peptide is secreted into saliva.     

Cholecalciferol metabolites binding in porcine parathyroid glands.

We studied the cytoplasmic and nuclear binding of 25-hydroxychole-calciferol and 1alpha,25-dihydroxycholecalciferol inside porcine parathyroid glands. Both sterols bind to cytoplasmic components, but a specific nuclear uptake was demonstrated only for 1alpha,25-dihydroxycholecalciferol. These findings support the hypothesis that mammalian parathyroid glands are a target organ for some cholecalciferol metabolites.