RESUMO
We evaluated the expression of glial fibrillary acidic protein (GFAP), glutamine synthetase (GS), ionized calcium binding adaptor protein-1 (Iba-1), and ferritin in rats after single or repeated lipopolysaccharide (LPS) treatment, which is known to induce endotoxin tolerance and glial activation. Male Wistar rats (200-250 g) received ip injections of LPS (100 µg/kg) or saline for 6 days: 6 saline (N = 5), 5 saline + 1 LPS (N = 6) and 6 LPS (N = 6). After the sixth injection, the rats were perfused and the brains were collected for immunohistochemistry. After a single LPS dose, the number of GFAP-positive cells increased in the hypothalamic arcuate nucleus (ARC; 1 LPS: 35.6 ± 1.4 vs control: 23.1 ± 2.5) and hippocampus (1 LPS: 165.0 ± 3.0 vs control: 137.5 ± 2.5), and interestingly, 6 LPS injections further increased GFAP expression in these regions (ARC = 52.5 ± 4.3; hippocampus = 182.2 ± 4.1). We found a higher GS expression only in the hippocampus of the 6 LPS injections group (56.6 ± 0.8 vs 46.7 ± 1.9). Ferritin-positive cells increased similarly in the hippocampus of rats treated with a single (49.2 ± 1.7 vs 28.1 ± 1.9) or repeated (47.6 ± 1.1 vs 28.1 ± 1.9) LPS dose. Single LPS enhanced Iba-1 in the paraventricular nucleus (PVN: 92.8 ± 4.1 vs 65.2 ± 2.2) and hippocampus (99.4 ± 4.4 vs 73.8 ± 2.1), but had no effect in the retrochiasmatic nucleus (RCA) and ARC. Interestingly, 6 LPS increased the Iba-1 expression in these hypothalamic and hippocampal regions (RCA: 57.8 ± 4.6 vs 36.6 ± 2.2; ARC: 62.4 ± 6.0 vs 37.0 ± 2.2; PVN: 100.7 ± 4.4 vs 65.2 ± 2.2; hippocampus: 123.0 ± 3.8 vs 73.8 ± 2.1). The results suggest that repeated LPS treatment stimulates the expression of glial activation markers, protecting neuronal activity during prolonged inflammatory challenges.
Assuntos
Animais , Masculino , Ratos , Proteínas de Ligação ao Cálcio/efeitos dos fármacos , Ferritinas/efeitos dos fármacos , Proteína Glial Fibrilar Ácida/efeitos dos fármacos , Glutamato-Amônia Ligase/efeitos dos fármacos , Hipocampo/efeitos dos fármacos , Hipotálamo/efeitos dos fármacos , Neuroglia/metabolismo , Biomarcadores/metabolismo , Proteínas de Ligação ao Cálcio/metabolismo , Ferritinas/metabolismo , Proteína Glial Fibrilar Ácida/metabolismo , Glutamato-Amônia Ligase/metabolismo , Hipocampo/química , Hipocampo/citologia , Hipotálamo/química , Hipotálamo/citologia , Imuno-Histoquímica , Lipopolissacarídeos , Neuroglia/efeitos dos fármacos , Ratos WistarRESUMO
Analisou-se o risco de se contrair leishmaniose visceral (LV) e a presença de animais em residências de Belo Horizonte/MG, em 2006. O estudo de caso-controle foi feito por meio de visitas domiciliares, aplicação de questionário e registro de imagens da residência. A estimativa de risco foi mensurada por comparação de condições de moradia entre dois grupos: 1- constituído por 82 casos humanos de LV ocorridos em 2004 e 2- 164 controles (vizinhos dos casos). Os domicílios pertencentes ao grupo 1 foram os que apresentaram os maiores percentuais de presença de animais. Observou-se, pela análise univariada, que a presença de patos, roedores, pássaros e galinhas aumenta o risco de ocorrer LV em 4,18; 1,81; 1,57; e 1,47 vezes, respectivamente. Para os proprietários de cães, o aumento no risco de contrair LV é equivalente a 2,17 vezes e está relacionado ao número de cães no domicílio. O risco de contrair LV é maior 1,87 vezes para moradores com um cão e 3,36 vezes para moradores com dois cães, quando comparados a pessoas que não possuem esses animais.
This study evaluated the animal presence in dwellings and the risk for transmission of visceral leishmaniasis (VL) in Belo Horizonte, Brazil, 2006. A case-control study was conducted by means of dwelling visits, direct interviews, and image register in the houses. The risk estimates were produced comparing the dwelling condition between two groups: 1) 82 human cases of VL recorded in 2004; and 2) 164 controls (neighbors of the first). The cases presented a higher proportion in the animal presence compared to controls. Using an unconditional logistic regression, it was selected the presence of ducks with an OR of 4.18 (CI 95 percent - 0.74 to 23.32); rodents with an OR of 1.81 (CI 95 percent - 0.96 to 3.39); birds with an OR of 1.56 (CI 95 percent - 0.90 to 2.69), and chicken with an OR of 1.47 (CI 95 percent - 0.74 to 2.90). The owners of dogs were 2.17 more likely to have VL than those who did not have dogs, and this estimate increased with the number of dogs in the house. For those who had only one dog, the OR was 1.87, while for those who owned two dogs at home, the OR increased to 3.36; when compared to people who did not own those animals.