RESUMO
This study was carried out in order to investigate the effect of testosterone administration on the regenerative power of the extirpated submandibular gland of rats. Thirty two Spargue-Dawley rats weighting about 240 gm were divided into two groups, 16 animals for each. In group 1 about half of right submandibular gland was removed and the animals were injected intraperitoneally at five successive days by testosterone. At different intervals [1,7,15 and 30 days] four rats were sacrified. Morphological and histochemical studies revealed healing of the extirpated area occured as a result of regeneration of secretory part by formation of newly formed serous acini from the old ones at the line of section and from rudimentary ducts in the central area. In the central area, the periductal cells were transformed into acinar cells and later, some of the straited ducts changed further to form granular convoluted tubules. In our study, group II revealed progressive newly formed acini and ducts. Some of these ducts demonstrated apical vacuolization within the first period, which could be considered as earlier sign of transformation into granular convoluted tubules, which appeared in later period in control groups. The lumina of these ducts appeared with eosinophilic products, which might indicate either that lumina carry acinar secretions or producing such material. The acini of group II became larger and its cytoplasm appeared as honeycombed appearance due to fusion of the secretory granules together. The appearance of the mucous cells or acini in group II may arise either from the proliferation of the already found mucous cells or as a result of sexual maturity. The newly formed acini showed strong PAS reaction, which decreased with maturation, denoting increase in the metabolic activity. The study has demonstrated that after testosterone administration the regenerative process of the submandibular gland was accelerated