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Binding patterns of lectins conjugated with horseradish peroxidase were studied on rabbit oviduct after mating and during pregnancy. The results of this research demonstrated beyond any doubt that the oviduct in the first days after mating and during the gestation period undergoes enormous changes at both surface and cytoplasmic carbohydrates. All the lectins used displayed modifications in the intensity of their reactivity, but the most interesting information was that concerning PNL, SBL and Con A lectins which showed remarkable differences in the behaviour of glycosidic residues in ampulla and isthmus.

In larvae of Ascidia malaca that have developed in sea-water without sulphate ions, the cells of the caphalo-ventral region are devoid of sulphated mucopolysaccharides, and the chordal and muscular cells of the tail turn out to be altered; after metamorphosis no adhesive ampullae appear. The addition of cysteine to water lacking sulphate ions leads to a normal synthesis of sulphated mucopolysaccharides in the cells of the cephalo-ventral region, and to a normal secretion of matrix by the chordal cells; but the larvae do not regain the ability to swim. The addition of N-dichloroacetyl-DL-phenylalanine to sea-water does not alter the synthesis of sulphated mucopolysaccharides in the cells of the cephalo-ventral region, but, probably by acting as a competitive inhibitor of phenylalanine, it causes alterations in the muscular cells of the tail.

Biochemical and histochemical analyses were carried out on the carbohydrate components of hare (Lepus europaeus) oviduct in anoestrous condition. Biochemical tests demonstrated that all the glycosidic components typical of glycoproteins and glycosaminoglycans are present in the ampulla and in the isthmus regions of oviduct, and that statistically significant differences exist in the sugar content between these two regions. In addition, lectin histochemistry combined with glycosidase digestion and selective histochemical stainings provided a series of rather detailed information on the localization of different neutral sugars and aminosugars. Hypotheses are advanced on the probable meaning of the different composition of ampullary and isthmic glycoconjugates in relation to the physiologically differentiated roles of the two oviduct tracts.

Biochemical and histochemical studies were carried out on the mouse submandibular gland to define the presence and the localization of glycosidic residues. The results obtained by applying peanut, winged pea, wheat germ, soybean and Con A lectins to unfixed and fixed sections tallied completely with biochemical determinations of the various glycosidic residues. The data from this study have been compared with those obtained by other authors who had performed biochemical and histochemical studies on the gland; similarities and discrepancies as to the presence and the localization of the sugars are discussed.