Degranulation of granular convoluted tube cells in mouse submandibular gland

The mechanism of irradiation-induced damage of salivary gland is still an enigma. One of the first hypothesis, which try to explain short-term effects, was degranulation. This hypothesis promote transition metal ions, such as Fe2+ and Cu2+, that are in same way associated with secretion granules, as injuries agent. In our previously investigation we didn’ t observe degranulation of granular convoluted tube (GCT) cells in irradiated mice submandibular gland 1 day after irradiation. Objective: The aim of this study was to investigate the degranulation of GCT in mouse submandibular gland after different protocols. Materials and methods: C57BL/6 male mice were divided in 5 groups: Group I-anaesthetized with sodium pentobarbital i.p., irradiated with single dose 15 Gy, chow and water ad libidum and sacrificed 24 hour after irradiation, Group II-anaesthetized and sacrificed after wake up, Group III-anaesthetized and left 24 hour without chow and water, Group IV-anaesthetized and left 24 hour with limited chow and water, Group V-control animal, without any treatment. The submandibular glands were analyzed morphologically. Results: In irradiated glands (group I), vacuolization was noted in acinar cell. Kariopiknotic nuclei were found in acini, GCT and intercalated ducts. In group I and V we didn’ t observe degranulation of GCT, while in group II GCT were degranulated. In group III and IV we observed partially degranulation. Other structures of submandibular gland in group II, III, IV and V appeared normal. Conclusion: These results suggest that anaesthesia and limited chow and water intake maybe reason for degranulation of GCT in salivary glands.