RESUMO
Abstract Purpose: To evaluate the effect of remote ischemic preconditioning (r-IPC) administered to pregnant rats, in the ileum of newborn rats subjected to hypoxia and reoxygenation. Methods: We used three pregnant rats and their newborn rats distributed in three groups: 1) Control (C) - Newborn rats born from a pregnant rat which did not undergo any intervention; 2) Hypoxia-Reoxygenation (H/R) - Newborn rats born from a pregnant rat which did not undergo any intervention, and were subjected to hypoxia-reoxygenation; 3) Remote Ischemic Preconditioning (r-IPC) - newborn rats born from a pregnant rat which was subjected to remote ischemic preconditioning twenty-four hours before giving birth and the newborn rats were subjected to hypoxia-reoxygenation. Segments of ileum were prepared for histological analysis by HE and immunohistochemistry by the Ki67 to evaluate cell proliferation, crypt depth and villus height and evaluation of apoptosis by cleaved caspase-3. Results: The intensity of the lesions was lower in the r-IPC than in the H/R group, showing significant difference (p<0.01). The r-IPC group showed a higher proliferative activity compared to the H/R group (p<0.01), with deeper crypts (r-IPC > H/R - p < 0.05), and higher villi, showing significant difference (r-IPC > H/R - (p <0.01). The occurrence of apoptosis in the H/R group was lower in comparison to groups C and r-IPC, with significant difference (H/R < r-IPC; p<0.05). Conclusion: The remote ischemic preconditioning applied to the pregnant rat protected the ileum of newborn rats subjected to hypoxia and reoxygenation, with decreased intensity of the lesions in the ileum mucosa and preservation of proliferative activity, keeping the villus height and crypt depth similar to group C.
Assuntos
Animais , Feminino , Ratos , Precondicionamento Isquêmico/métodos , Enterocolite Necrosante/prevenção & controle , Íleo/irrigação sanguínea , Fatores de Tempo , Gravidez , Imuno-Histoquímica , Traumatismo por Reperfusão/prevenção & controle , Hipóxia Celular , Reprodutibilidade dos Testes , Resultado do Tratamento , Apoptose , Antígeno Ki-67/análise , Enterocolite Necrosante/patologia , Modelos Animais de Doenças , Caspase 3/análise , Íleo/patologia , Mucosa Intestinal/irrigação sanguínea , Animais Recém-NascidosRESUMO
O trabalho apresenta cinco modelos de produçäo de aderências estudados comparativamente, em ratos. Foram utilizados 140 ratos da linhagem Wistar, divididos em 7 grupos de 20 ratos: 1) contrôle; 2) iintroduçäo de soro fisiológico e manuseio das alças intestinais; 3) sangue na cavidade peritoneal; 4) escarificaçäo de um segmento intestinal; 5) duas ligaduras vaculares de um segmento instetinal; 6) três ligaduras vasculares de um segmento intestinal; 7) introduçäo de talco na cavidade peritoneal. Os animais foram re-operados no 7§, 14§ e 21§ dias pós-operatório. O grupo da escarificaçäo de um segmento intestinal apresentou maior porcentagem de aderencias peritoneais. Nos grupos submetidos a duas e três ligaduras vasculares observou-se uma provável correlaçäo entre a hipóxia e aderências peritoneais