Abstract The effects of high and low-protein diets on the structure of the jejunal mucosa were studied in Schistosoma mansoni infected mice (morphology and histomorphometry). Weaning male albino mice

The effects of high and low-protein diets on the structure of the jejunal mucosa were studied in Schistosoma mansoni infected mice (morphology and histomorphometry). Weaning male albino mice were infected with 80 cercariae, fed with high (20%) or low-protein (5%) diets and compared to uninfected controls under the same conditions. Mice were sacrificed 12 weeks after infection. Animals submitted to a low-protein diet showed lower weight curves, mainly when infected. In the jejunal mucosa, finger-like villi were the predominant pattern among uninfected high-protein fed animals, while the infected ones showed leaf-shaped and flattened villi in most cases. Undernourished infected mice had 65.7% leaf-shaped villi. A significant increase in the number of goblet cells was seen in infected mice. A decrease in the number of absorptive cells was detected in undernourished mice, particularly in infected ones. Key-words: Schistosoma mansoni. Undernutrition. Mice. Intestinal mucosa. Histomorphometry. Resumo Os efeitos de dietas hiper e hipoprotéica sobre a estrutura da mucosa jejunal de camundongos infectados com Schistosoma mansoni foram estudados por métodos histológicos e histomorfométricos. Camundongos albinos, machos, recém-desmamados, foram infectados com 80 cercárias e alimentados com dietas hiper (20%) ou hipoproteica (5%) e comparados com controles não-infectados, nas mesmas condições, sendo sacrificados após 12 semanas de infecção. Animais em dieta hipoproteica tiveram curvas ponderais menos elevadas, sobretudo quando infectados. A mucosa do jejuno mostrou predominância de vilosidades digitiformes nos camundongos não infectados, recebendo dieta hiperprotéica; vilosidades foliáceas foram mais numerosas nos desnutridos infectados (65,7%). Nas vilosidades dos animais infectados, ocorreu significativo aumento no número de células caliciformes. Entre os desnutridos foi detectada redução do número de enterócitos, condição agravada pela infecção. Palavras-chaves: Schistosoma mansoni. Desnutrição. Camundongo. Mucosa intestinal. Histomorfometria. 1. Departamento de Parasitologia do Centro de Ciências Biológicas da Universidade Federal de Alagoas, Maceió, AL. 2. Departamento de Nutrição do Centro de Ciências da Saúde da Universidade Federal de Alagoas. Maceió, AL. 3. Escola de Ciências Médicas de Alagoas, Maceió, AL. 4. Departamento de Patologia da Universidade Federal Fluminense. Niterói, RJ. 5. Centro de Pesquisas Aggeu Magalhães da Fundação Oswaldo Cruz, Recife, PE, Brasil. Financial support from the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) and Fundação de Amparo à Pesquisa do Estado de Alagoas (FAPEAL). Address to: Dr. Haroldo S. Ferreira. R. Des. Almeida Guimarães 37, Pajuçara, 57030-160 Maceió, AL, Brasil. Tel: 55 82 214-1165; 337-4481/9381-2731; Fax: -55-82 214-1665. e-mail: [email protected] Recebido para publicação em 27/09/2001. Schistosomiasis and malnutrition are public health problems of major concern in underdeveloped countries and usually overlap in many endemic areas of the world7 8 9. Previous papers have shown the importance and frequency of intestinal lesions in schistosomiasis mansoni, not only in man15 19 31 but also in experimental animals13 30. An intestinal malabsorption syndrome has been detected by some authors in the hepato-splenic clinical form of the disease in humans26 28 and in infected mice . Structural changes of the small intestine have been repor ted in human4 5 22 24 26 and exper imental schistosomiasis9, as well as in undernutrition2 23 35 36 37. However, the relationships between schistosomiasis infection and the nutritional status of the host are not quite clear at the present time, mainly regarding the