Ação da toxina botulínica tipo A em glândula submandibular de ratos

Abstract

The aim of this study was to observe the morphometric, histological and histométricos aspects of submandibular glands of rats treated with botulinum toxin type A (BTX-A) and with bovine gelatin. We used 80 submandibular glands of adult Wistar rats and divided into three groups: group I, control (n = 14); group II (n = 34) submitted the intraglandular injection of bovine gelatin (0.25 mg); and group III (n = 32) treated with intraglandular injection of botulinum toxin type A (2.5 U). The groups II and III were divided into 3 subgroups according to the day of analysis of glands (7, 15 and 28 days after treatment), when they were removed, heavy and measures immediately for morphometric analysis. Next, were fixed in paraformaldehyde 4 % and processed conventionally for light microscopy, stained in H.E., P.A.S., alcian blue, Gomori trichrome and picrosirius red. Morphometric differences were not observed between subgroups of group III, however in group II there was a significant difference between the three subgroups in the longitudinal length (p = 0.030) and transverse length (p = 0.025), having the gland has shown greater at day 28th after treatment. Histometrically, serous and mucous acini group III, were presented with a smaller diameter compared with the acinithe subgroups treated with bovine gelatina (group II). The wall thickness of the striated duct Group III was lower than in other. Histologically, there was a greater amount of cytoplasmic vacuolization in group III. addition to the greater spacing between the acini. Thus, we conclude that botulinum toxin type A interferes with the structural organization of the submandibular glands, promoting a reduction in the diameter of serous acini and in wall thickness striated ducts, macroscopically but this difference was not significant.