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Sugar specific lectins (PNA, RCA I, LPA, SBA, DBA, GSA IB4, GSA II, WGA, LTA, UEA I, Con A, LCA) with and without prior selective glycosidase digestion (sialidase, alpha-fucosidase, alpha-mannosidase, beta-N-acetylglucosaminidase, alpha- and beta-galactosidase, beta-glucosidase) were used in order to investigate the distribution of native accessible carbohydrates and obtain information dealing with the composition of terminal disaccharides within glycoconjugates present in acinar compartments and ductal segments of mammalian (mouse, rat, hare, and rabbit) parotid glands. Glycoconjugates containing variable amounts of mannose, glucose, N-acetylgalactosamine and N-acetylglucosamine were present in the parotid glands of all species. However, these carbohydrate chains exhibited a different composition of terminal sequences within each type of gland. For example, sialylated components having the terminal dimers sialic acid-galactose and sialic acid-N-acetylgalactosamine were found in all acinar cells, whereas fucoglycoconjugates with terminal disaccharide fucose-galactose were localized in the rat striated ducts and hare acinar cells. The terminal sequence alpha-galactose-beta-galactose was demonstrated in the mouse acinar cells. Finally, glycoconjugates characterized by the terminal dimer beta-galactose-N-acetylgalactosamine were demonstrated in the mouse acinar and ductal cells and the rat ductal ones. Thus, present findings outlined and further confirmed the possibility to elucidate the oligosaccharide structure in situ using lectin histochemistry combined with enzymatic degradation.

Summary We investigated the occurrence of endogenous lectins in the mouse submandibular gland using anti-lectin antibodies that selectively bound the respective hapten lectins which have formed a complex with the appropriate hapten sugars and endogenous lectins. Findings supported the idea that endogenous lectins could interact with sugar residues and perform several roles including packaging, immobilization and transport of glucidic material. A functional meaning in the defence from some pathogenous agents was also postulated. Animal lectins seem to play roles related to their localization like occurs in the plants.

Summary An investigation was carried out by light and electron microscopy on the localization of the carbonic anhydrase enzyme in the submandibular and sublingual glands of some rodents and lagomorpha. By means of the cobalt-bicarbonate technique, it was demonstrated that in the submandibular glands the carbonic anhydrase activity is more intense in the terminal tracts, and that in the sublingual glands the enzyme activity is present in an equal degree in the terminal tracts and in the intralobular ducts. The results obtained are compared to those of other authors, and conjectures are made as to the functional significance of the carbonic anhydrase activity in the salivary glands.

In order to verify the influence of fixative on the formation of any nonspecific lectin bindings, the authors have carried out an investigation on rabbit salivary glands. The results obtained applying peanut, soybean, wheat germ, and winged pea lectins to unfixed samples of rabbit submandibular and sublingual glands agreed almost completely with the results of our previous research effected on the same samples fixed with aldehydes. The most important differences between the fixed samples and the unfixed ones consisted in the lack of reactivity of the material inside the secretion lumina to all the lectins used, and in the lack of peanut binding to the submandibular gland. No significant differences in intensity and location were found for soybean, wheat germ, and winged pea lectins.

Summary A histochemical study was effected, by light and electron microscopy, on the activity of arylsulphatases A and B in the submandibular and sublingual glands of male and female rabbits, distinguishing, among the latter, between the physiological estrus and anestrus condition. The results obtained demonstrated that the enzymatic activity is more intense in the sublingual gland and that the estrus condition causes an increase in this activity. No correlation was found between the topochemical distribution of the soluble arylsulphatases and that of sulphates.

Summary The carbohydrate histochemistry of rabbit submandibular and subungual glands has been examined by the use of 4 peroxidase-labeled lectins at the light microscopic level. In the submandibular gland, the striated ducts appeared to be the formations which were more reactive to all lectins. In the sublingual gland, the terminal tracts were the most reactive secreting portions, because they bound all the lectins used. The material contained in the lumen of the ducts of submandibular and sublingual glands always reacted fairly intensely. The binding of lectins to salivary glands indicated the possibility to use lectins for the explanation of the transport properties both of the striated ducts and of the terminal tracts.

A histochemical study has been carried out by light and electron microscopy on the localization of the activity of arylsulphatases A and B in the salivary glands of rat. Results obtained indicate that in the submandibular gland a greater activity is present in the cells of the convoluted granular tubules than in the acina cells, whereas in the sublingual gland the cells of the preterminal tracts appear to be more reactive than those of the terminal tracts. The probable role played by these sulphatases is discussed.

Summary Stainings with dialized iron (DI), high-iron diamine-thiocarbohydrazide-silver proteinate HID-TCH-SP), tannic acid-uranylacetate (TA-U), tannic acid-ferric chloride (TA-F), and periodate- thiocarbohydrazide-silver proteinate (P A-TCH-SP) were applied to samples of sublingual glands of rabbits. Comparing the results obtained with what had been previously demonstrated biochemically, it is possible to assert that the faintly electron-opaque, granules of the cells of the preterminal tracts contain sulphated glycoconjugates because of the presence of sulphated hexosamines and hexoses, acid glycoconjugates because of the presence of sialic acid and uronic acids, and neutral glycoconjugates because of the presence of hexoses.

We investigated the structure of glycoconjugates contained within the secretory end-pieces and ductal segments in the rabbit submandibular and sublingual glands. Glycosidic sequences were examined by means of enzymatic degradation with specific glycosidases (sialidase, alpha-fucosidase, beta-galactosidase, alpha-mannosidase) followed by lectin binding with PNL-HRP, WPL-HRP, WGL-HRP, SBL-HRP, Con A-HRP. It was found that this procedure represents a valid tool for studying carbohydrates, in so far as their characterization and localization were based only on colour reactions. In particular, this research showed that sialic acid was present in the terminal dimers sialic acid-beta-galactose and sialic acid-N-acetyl-D-galactosamine within the submandibular gland, whereas in the sublingual gland it was only present as the sequence sialic acid-beta-galactose. Conversely, fucose had as the subterminal sugar N-acetyl-D-glucosamine in both glands. Also, elucidations about structural sequences concerning other non-terminal sugars were obtained.

Summary An ultrastructural histochemical study was carried out on submandibular glands of rabbits.Stainings were performed with dialysed iron (DI), high iron diamine (HID), tannic acid uranyl acetate (TA-U), tannic acid-ferric chloride (TA-F) sequence, and periodate-thiocarbohydrazidesilver proteinate (PA-TCH-SP) method. It was demonstrated that neutral glycoproteins are present in the cells with dark granules of the preterminal tracts, and that neutral and acid glycoproteins are present in the cells with light granules of the terminal tracts.Result are discusSed and compared to other previously obtained histochemical and biochemical data.

Specimens from rat ampulla and isthmus were stained with a battery of 10 lectin-horseradish peroxidase conjugates and lectin binding patterns were correlated with the distribution of periodate-reactive vicinal diol groups as determined by the PA-TCH-SP (periodic acid-thiocarbohydrazide-silver proteinate) sequence. The free surface of ciliated and non-ciliated cells was stained moderately to intensely by all lectins and PA-TCH-SP sequence. Binding sites for WGA, UEA I, LTA, Con A were also detected on the tight junctional regions. Secretory granules reacted with all stainings, except for LPA. The localization of certain sugars (sialic acid, fucose) appeared useful for understanding the functional meaning of positive sites.

Summary An investigation has been carried out on the activity of arylsulphatases A and B (ASA and ASB) in the oviduct of rabbits in anestrus and estrus conditions. The histochemical and biochemical results obtained have demonstrated that both arylsulphatases are present in the ampulla tract and in the isthmic one, and that the estrus determines a considerable increase in the specific activity of ASB. Hypothesis are advanced on the probable-meaning of the variations in the activity of these enzymes, particularly in relation to the secretion of glycoconjugates by the epithelium of the oviduct.

Stainings were effected on an ultrastructural histochemical level to localize sulphomucins in the submandibular and sublingual glands of growing mice and rabbits. Sulphates behave in an entirely different way in the salivary glands of Lagomorpha and in those of Rodents. In growing rabbits sulphates can be demonstrated in both glands; at maturity they can be demonstrated only in the sublingual gland and no longer in the submandibular gland. In the salivary glands of Rodents, sulphates cannot be demonstrated histochemically in new born subjects or in adults. The histochemical results are compared to the biochemical ones, and discrepancies, where present, are discussed.

A histochemical study was effected, by light and electron microscopy, on the activity of arylsulphatases A and B in the submandibular and sublingual glands of male and female rabbits, distinguishing, among the latter, between the physiological estrus and anestrus condition. The results obtained demonstrated that the enzymatic activity is more intense in the sublingual gland and that the estrus condition causes an increase in this activity. No correlation was found between the topochemical distribution of the soluble arylsulphatases and that of sulphates.

Summary An ultrastructural histochemical investigation was carried out to ascertain the localization of the glucidic components and to verify the histochemical modifications during the physiological estrogenic cycle of rabbit oviduct. Stainings were performed with high iron diamine (HID), low iron diamine (LID), dialized iron (DI), tannic acid-uranyl acetate (TA-U), and periodate-thiocarbohydrazide-silver proteinate (PA-TCH-SP) methods. The findings indicated that the secretory activity is more intense in the isthmus than in the ampulla. Neutral glycoconjugates are localized both in the secreting elements of the ampulla and in those of the isthmus, while carboxylated and sulphated glycosaminoglycans are localized only in the secretory granules of the secreting elements of the isthmus.

Summary The glycosidic residues in the submandibular gland of cat at different ages were studied using a battery of 6 lectins conjugated with horseradish peroxidase as histochemical reagents. The submandibular glands of sucking and adult cats showed diversities in the reaction intensity or in the localization of binding sites. The morphologically distinct secretory tracts appear to produce different types of oligosaccharides in sucking and adult subjects. The sugars that can be defined as growth markers in the cat submandibular gland seem to be α-L-fucose, N-acetyl-D-glycosamine and β-galactose. The data originated from this research have been compared with biochemical data previously obtained by the authors on the cat submandibular gland during growth.