ABSTRACT
O peso e a celularidade do timo foram estudados em camundongos C 57 BL/6 com 8 semanas de idade, tratados durante 48 horas com dieta parenteral (DP), jejum, injeçöes de salina, e raçäo comum e água "ad libitum". Os resultados mostraram que a DP levou a uma perda de peso do timo proporcionalmente maior que a perda de peso corporal e que a perda de peso do fígado. A comparaçäo entre os grupos mostrou que a proporçäo dessa perda em relaçäo ao peso corporal foi semelhante entre os animais submetidos à DP e ao jejum. Por outro lado, o número de timócitos foi muito mais elevado nos animais tratados com a DP que naqueles submetidos ao jejum, embora muito menor que nos animais alimentados "ad libitum".
Subject(s)
Animals , Male , Mice , Fasting/adverse effects , Parenteral Nutrition/adverse effects , Thymus Gland/anatomy & histology , Organ Size , Thymus Gland/cytologyABSTRACT
Adult mice were submitted to different degrees of protein restriction for five weeks (4.75, 9.5, 14.25 and 19 per cent of protein in isocaloric diets with normal content of mineral and vitamins), being subsequently infected with two strains of Trypanosoma cruzi: 10(5) trypomastigotes of Y strain or 10(4) trypomastigotes of CL strain. The same diet was maintained for all animals and the infection was followed up by evaluation of blood parasites, mortality and intensity of lesions in the heart and skeleton muscle. Only severe protein restriction (4.75 per cent ) induced decrease in resistance to the infection with both the Y and CL strains of T. cruzi, which resulted in higher parasitemia and mortality. The inflammatory lesions in heart and skeleton muscle were less extensive in groups with severe protein restriction despite the increased number of parasite in muscle cells. Depression of immune mechanisms could be responsible for the reduced resistance and reduced inflammatory reaction after T. cruzi infection in severely protein restricted animals