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A correlation between stressful events experienced by the mother during pregnancy and progression of respiratory disease in descendants has been reported. Prenatal exposure to lipopolyssacharide (LPS) reduces allergic airway inflammation in mice offspring. In this study we investigated whether reduction of airways inflammation by maternal LPS exposure involves activation of inducible nitric oxide synthase (iNOS) at prenatal life. Since LPS also induces the release of TNF-alpha, and that this cytokine has been implicated in pathogenesis of asthma, we also evaluated whether TNF-alpha plays a role in the allergic airways inflammation by maternal LPS exposure. Pregnant rats were pretreated with the iNOS inhibitor aminoguanidine (50mg/rat per day; given from day 13 of gestation up to delivery) before exposure to LPS (7mug/kg, given at day 17 of gestation). At adult ages, female and male offspring were sensitized with ovalbumin (OVA), and 14 days later they were challenged with this allergen. OVA challenge in sensitized offspring increased markedly the eosinophil number in bronchoalveolar lavage (BAL) fluid at 48h compared with the non-sensitized group. However, the eosinophil number was largely reduced in offspring from maternal LPS exposure, irrespective of offspring gender. Maternal pretreatment with aminoguanidine fully reversed the eosinophil suppression by LPS. The maternal LPS exposure also reduced the eosinophil number in bone marrow and peripheral blood of offspring, but this was not affected by aminoguanidine. No differences in TNF-alpha levels in BAL fluid were found. In conclusion, our study shows that maternal LPS exposure markedly reduces allergic airways eosinophil recruitment in adult offspring by mechanisms possibly involving iNOS activation.

The effects of chronic unpredictable stress on airway leukocyte infiltration and plasma extravasation in female rats have been investigated. The chronic stress lasted for 14 days and consisted of transitory and variable changes in the living conditions of the animals. Concomitant to the stress procedure, the animals were sensitized (Day 0) and challenged with ovalbumin (OVA; 200 microg) at Day 14. Bronchoalveolar lavage (BAL) was performed 48 h after intratracheal challenge with OVA (0.4 ml of a 0.25% solution). The increase in plasma extravasation was assessed by the rat paw oedema induced by OVA (0.1 mg/paw) or the mast cell degranulator compound 48/80 (5 microg/paw). A significant increase (P.05) in the total leukocyte influxes into the airways was observed in the stressed (sensitized) group compared to nonstressed (sensitized) animals, and this was associated with a marked recruitment of eosinophils and mononuclear cells in the BAL fluid. In OVA-sensitized rats, intraplantar injection of OVA induced a marked paw oedema that was significantly higher in stressed compared to nonstressed groups. In contrast to OVA, the compound 48/80 (5 microg/paw)-induced oedema did not significantly differ between nonstressed and stressed groups. Our results indicate that chronic unpredictable stress exacerbates the vascular and cellular inflammatory responses.

Orientadores: Nancy Airoldi Teixeira, Edson Antunes Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas Resumo: Neste trabalho investigamos o efeito do estresse crônico pré-natal sobre a resposta inflamatória em ratos. Ratas Wistar prenhes foram submetidas ao modelo de estresse proposto por WllLNER et alo(1987), que consistia de alterações variadas e transitórias no ambiente de criação dos animais durante as duas últimas semanas de gravidez, o grupo controle permaneceu sem qualquer manipulação, exceto os cuidados rotineiros. Os descendentes, entre 75 e 90 dias, foram submetidos aos seguintes testes: edema de pele, edema de pata, pleurisia não alérgica e pleurisia alérgica. Para o protocolo de pleurisia alérgica, os animais foram sensibilizados no primeiro dia do protocolo de estresse com uma injeção subcutânea de ovoalbumina (OVA), após o último dia do protocolo de estresse os animais eram desafiados com OVA na cavidade pleural. A pleurisia não alérgica foi induzida com carragenina, o edema de pata foi induzido com carragenina ou C48/80 e o edema de pele foi induzido com PAF, LPS, carragenina e C48/80. Na pleurisia alérgica o lavado pleural foi coletado 24h após o desafio antigênico com OVA, no procedimento de pleurisia não alérgica, o lavado pleural foi coletado 6, 24 e 48h após indução com carragenina. As medidas do volume das patas para o edema foram realizadas 60, 120, 180,240 e 300min após a indução com carragenina e 15, 30, 60, 120 e 180min pam 0.C48/80. Os resultados demonstraram que não houve diferença significativa entre os grupos estressados e não estressados n o teste de edema de pele. No edema de pata induzido por C48/80, a resposta edematogênica foi diminuída, já quando o estímulo foi carragenina a resposta não foi alterada. Na pleurisia não alérgica, os animais prenatalmente estressados apresentaram um significativo aumento no influxo de eosinófilos em comparação aos animais não estressados no tempo de 24h. Na pleurisia alérgica os ratos prenatalmente estressados exibiram uma exacerbação no infiltrado de leucócitos, esta ocorreu em todos os tipos celulares estudados: neutrófilos, eosinófilos e células mononucleares Abstract: In this work we investigated the chronic mild prenatal stress effect on the vascular and cellular inflammatory response in rats. Pregnant female Wistar rats were submitted to the stress model proposed by WILLNER et al., 1987, that consisted of varied and transitory alterations of the environment of creation of the animals in the last 2 weeks of gestation, the control group stayed without any manipulation, except routine cares. The adults offspring were submitted to the following tests: skin oedema, paw oedema, non allergic pleurisy, allergic pleurisy. To the allergic pleurisy protocol, the animals were sensitized in the first day of stress protocol with a subcutaneous injection of ovalbumin (OVA), after the last day of the stress protocol the animals were challenged with OVA in the pleural cavity. The non-allergic pleurisy was induced by carrageenan, the oedema was induced by carrageenan or C48/80 and the skin oedema with PAF, LPS, carrageenan and C48/80. In the allergic pleurisy de pleural lavage was collected 24h after the antigenic challenge with OVA, in the non-allergic pleurisy procedure the pleural lavage was collected 6, 24 and 48h after induction by carrageenan. The volume of paws measure to non-allergic paw oedema was performed 60, 120, 180, 240 and 300min after induction by carrageenan and 15,30,60, 120 and 180min for C48/80. The results showed not significant difference between the stressed and non-stressed groups in the skin oedema to all stimulus. Already, the edematogenic response was diminished to the prenatally stressed rats in comparison to the non-stressed in the paw oedema induced C48/80, but not in the rats were stimulated with carrageenan. The non-alIergic pleurisy showed a significant enhancement in the eosinophils infiltration 24h challenge with carrageenan in prenatally stressed rats. In the allergic pleurisy the prenatally stressed rats exhibited a significant exacerbation in the leukocytes influx, differentially this exacerbation occurred to all cellular types studied: neutrophils, eosinophils and mononuclear cells Mestrado Mestre em Farmacologia