Ultrastructure, ultracytochemistry and histochemistry of the submandibular gland of the red-backed vole

Abstract

The submandibular glands of adult female and male red-backed vole (Clethrionontys rufocanus bedfordiae THOMAS) were studied histochemically, ultracytochemically and ultrastructurally in order to detect the ultrastructure and secretory nature of their granules belonging to each part and also to detect the presence of sexual dimorphism of convoluted granular tubules (CGT). The submandibular gland consisted of the excretory ducts, the striated ducts (SD), CGT, the intercalated ducts (ID) and the terminal portions. In both sexes, the acinar cells were classified specially serous cells in secretory nature, and the secretory granules contained glycoproteins and were negative to amylase and protease activities. By the PA-TSC-SP staining, the distribution of glycoproteins in acinar cells was demonstrated. The grnules of the ID cells have bipartite structures consisting of a dense homogenous core and the peripheral rim of a less dense, filamentous structure. The former contained protein and the lattar contained neutralmucosubstance. The granules of CGT cells contained tryptophan, tyrosine and neutralmucopolysaccharide. The granules of the CGT cells were negative to reaction for acid mucopolysaccharides, protease and amylase activities and glycoproteins (20°C) and decreased their electron-density by pronase digestion. Furthermore, by the PA-TSC-SP staining (60°C), the granules of ID and CGT cells were positive to the reactions of the glycoproteins. In the SD cells, secretory vesicles were in the clear cell and reabsorption vesicles and smooth surfaced cisterns were in the dark cells. From the statistical analysis of the average values, the CGT diameter of the male red-backed vole was significantly larger than that of female vole.