RESUMO
It has been demonstrated that the acute phase of Trypanosoma cruzi infection promotes several changes in the oral glands. The present study examined whether T. cruzi modulates the expression of host cell apoptotic or mitotic pathway genes. Rats were infected with T. cruzi then sacrificed after 18, 32, 64 or 97 days, after which the submandibular glands were analyzed by immunohistochemistry. Immunohistochemical analyses using an anti-bromodeoxyuridine antibody showed that, during acute T. cruzi infection, DNA synthesizing cells in rat submandibular glands were lower than in non-infected animals (p < 0.05). However, after 64 days of infection (chronic phase), the number of immunolabeled cells are similar in both groups. However, immunohistochemical analysis of Fas and Bcl-2 expression did not find any difference between infected and non-infected animals in both the acute and chronic stages. These findings suggest that the delay in ductal maturation observed at the acute phase of Chagas disease is correlated with lower expression of DNA synthesis genes, but not apoptotic genes.
Assuntos
Doença de Chagas/patologia , DNA/biossíntese , Glândula Submandibular/parasitologia , Animais , Apoptose , Bromodesoxiuridina/metabolismo , Doença de Chagas/metabolismo , Proteína Ligante Fas/biossíntese , Imuno-Histoquímica , Masculino , Proteínas Proto-Oncogênicas c-bcl-2/biossíntese , Ratos , Glândula Submandibular/metabolismo , Glândula Submandibular/patologia , Fatores de TempoRESUMO
It has been demonstrated that the acute phase of Trypanosoma cruzi infection promotes several changes in the oral glands. The present study examined whether T. cruzi modulates the expression of host cell apoptotic or mitotic pathway genes. Rats were infected with T. cruzi then sacrificed after 18, 32, 64 or 97 days, after which the submandibular glands were analyzed by immunohistochemistry. Immunohistochemical analyses using an anti-bromodeoxyuridine antibody showed that, during acute T. cruzi infection, DNA synthesizing cells in rat submandibular glands were lower than in non-infected animals (p < 0.05). However, after 64 days of infection (chronic phase), the number of immunolabeled cells are similar in both groups. However, immunohistochemical analysis of Fas and Bcl-2 expression did not find any difference between infected and non-infected animals in both the acute and chronic stages. These findings suggest that the delay in ductal maturation observed at the acute phase of Chagas disease is correlated with lower expression of DNA synthesis genes, but not apoptotic genes.
Assuntos
Animais , Masculino , Ratos , Doença de Chagas/patologia , DNA , Glândula Submandibular/parasitologia , Apoptose , Bromodesoxiuridina/metabolismo , Doença de Chagas/metabolismo , Proteína Ligante Fas/biossíntese , Imuno-Histoquímica , /biossíntese , Glândula Submandibular/metabolismo , Glândula Submandibular/patologia , Fatores de TempoRESUMO
We have previously demonstrated in rats that Chagas' disease affects the salivary glands, by promoting an enlargement of the submandibular gland. In order to further investigate possible functional alterations on infected submandibular glands, the objective of the present study was to analyze epidermal growth factor (EGF) expression on rat submandibular glands during Trypanosoma cruzi infection. Results demonstrated that infected rats presented lower levels of testosterone, and morphological changes in the granular convoluted tubule (GCT) cells of the submandibular glands, along with acinar enlargement and delayed ductal maturation at the developing granular ducts. Immunohistochemistry analysis additionally showed that only few cells immunolabelled with anti-EGF on infected rats during the acute phase of Chagas' disease, while after 64 and 90 days (chronic phase) of infection, EGF expression was similar to non-infected rats. The present findings suggest that at the acute phase of Chagas' disease, lower levels of testosterone may lead to a delayed maturation of GCT, which positively correlates with decreased EGF production by submandibular glands cells.
Assuntos
Fator de Crescimento Epidérmico/metabolismo , Glândula Submandibular/patologia , Glândula Submandibular/parasitologia , Trypanosoma cruzi/fisiologia , Animais , Peso Corporal , Doença de Chagas/parasitologia , Doença de Chagas/patologia , Imuno-Histoquímica , Masculino , Ratos , Glândula Submandibular/metabolismo , Testosterona/sangueRESUMO
Tissue parasitism, inflammatory process (histologic methods) and sympathetic denervation (glyoxylic acid-induced histofluorescence for demonstration of catecholamines) were studied in the heart (atrium and ventricle) and the submandibular gland of rats infected with the Y strain of Trypanosoma cruzi. In the heart paralleling intense parasitism and inflammatory process, the sympathetic denervation started at day-6 of infection and at the end of the acute phase (day 20) practically no varicose nerve terminals were found in both myocardium and vessels. In the submandibular gland, in spite of the rarity of amastigote pseudocysts and the scarcity of inflammatory foci, slight to moderate (days 13-15 of infection) or moderate to severe denervation (day 20) was found. At day 120 of infection both organs exhibited normal pattern of sympathetic innervation and only the heart showed some inflammatory foci and rare pseudocysts (ventricle). Our data suggest the involvement of circulating factors in the sympathetic denervation phenomena but indicate that local inflammatory process is, at least, an aggravating factor.