Intestinal protein absorption in malnourished mice with acute schistosomiasis mansoni

Abstract

Intestinal protein absorption was studied in undernourished albino Swiss mice with acute schistosomiasis mansoni. Undernutrition was induced by feeding mice with the Regional Basic Diet (RBD) ingested by human populations in Northeast Brazil, an experimental model previously developed in our laboratory. Weaning mice were infected with 40 cercariae and compared to undernourished non-infected mice and/or to infected mice fed a balanced control diet. Apparent and True Protein Absorption Coefficients were determined by nitrogen balance during five consecutive days ending at the 63rd day of the trial (acute phase of murine schistosomiasis). Fecal metabolic nitrogen (FMN) was determined after administration of a non-protein diet and was also calculated through linear regression. Our results showed a reduced protein absorption in non-infected RBD-fed mice as compared to mice fed a casein control diet. Infection with Schistosoma mansoni had apparently no effect on intestinal protein absorption in well-nourished mice. However, infection seemed to interfere with protein absorption in under-nourished animals, since the lowest absorption ratios have been detected among RBD-fed infected mice. A brief discussion is made on the advantages of using the method of linear regression for the determination of FMN.

Saúde de populações marginalizadas: desnutrição, anemia e enteroparasitoses em crianças de uma favela do "Movimento dos Sem Teto", Maceió, Alagoas

“…Correia e McAuliffe, 25 relatam estudos que demonstraram má-absorção intestinal em crianças infectadas por Giardia lamblia ou Ascaris lumbricoides, com prejuízos ao seu estado nutricional. Ferreira et al, 33 em estudo experimental com camundongos, verificaram que a esquistossomose não afetava a absorção intestinal de proteínas quando os animais recebiam dieta balanceada, porém agravava a má-absorção presente nos animais desnutridos pelo consumo de uma dieta multideficiente.…”

Parasitological characteristics of Schistosoma mansoni infection in swiss mice with underlying malnutrition

“…Difference in the wandering capacity of malnourished worms inside the portal system vessels could be responsible for the observed results (Valadares et al 1981). On opposite, it seems that schistosomiasis infection interferes with the process of intestinal protein absorption by potentiating the negative effects of malnutrition (Ferreira et al 1993). It is particularly noticeable that dietary restriction induces morphological and physiological changes on the digestive tract.…”

The use of protein hydrolysate improves the protein intestinal absorption in undernourished mice infected with Schistosoma mansoni

“…Calculations regarding faecal metabolic nitrogen were not taken into account, since previous investigation using the same experimental model had shown a high equivalence between apparent and true intestinal protein absorption 9 . Thus, for the objectives of this study, its influence was assumed to be negligible on the outcome results.…”