A more detailed observation was only possible at higher magnifications. The nuclei were pyknotic and hyperstained, a finding characterizing the typical chromatin condensation seen in apoptotic processes. The stroma was enlarged and contained smooth muscle cells and fibroblasts (Fig. 1D–F). This enhanced extracellular matrix accumulation was detected by birefringence, with the observation of the same colour pattern and a larger amount Enzalutamide price of type I collagen and a lower quantity of type III collagen when compared to the control group. The quantity of type II collagen was similar to that observed in healthy animals (Fig. 1F and

Table 3 and Table 6). The submandibular glands of control animals mainly consisted of seromucous acini that showed characteristics similar to those of the parotid gland. These seromucous acini consisted of groups of mucosal columnar cells with a truncated pyramid shape associated with serous demilune cells (Fig. 2A SD-208 and Table 4). The presence of dense, regularly arranged nuclei indicated a possible period of saliva production. The nuclei were mainly elliptical or spherical and

were located in the basal region. The intercalated ducts between acini were smaller than those of the parotid gland, a finding demonstrating the normal pattern of this gland (Fig. 2B). In addition, polarized light microscopy permitted the observation of a discrete stromal space. This space was filled with type I collagen that appeared as red and thick fibres, followed by types III and II collagen which appeared as thin, green and yellow fibres,

respectively (Fig. 2C and Table 5 and Table 6) (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of the article.). The submandibular glands of animals exposed to cigarette heptaminol smoke were characterized by pleomorphic and involuted seromucous acini that consisted of mucous and serous demilune cells. These cells were less defined when compared to control animals (Fig. 2D and Table 4). Intercalated ducts and an inflammatory infiltrate were also observed in this gland (Fig. 2D). The cytoplasmic components were poorly defined at higher magnification. The nuclei were pyknotic and hyperstained, a finding characterizing the typical chromatin condensation seen in apoptotic processes (Fig. 2E). The interacinar space was enlarged and the stroma presented extracellular matrix alterations, such as an increase of connective tissue, especially type I collagen, followed by types III and II collagen (Fig. 2F and Table 5 and Table 6). The action of cigarette components, especially nicotine, for a period of 10 days can lead to alterations in the digestive system.36 These alterations, in turn, interfere with food absorption, compromising the weight and nutrition of animals. In the present study, no significant differences in body weight variation were observed. Similar findings have been reported by Caldeira et al.