Intestinal enzymes during malnutrition & infection in rabbits.

BACKGROUND & OBJECTIVES: Malnutrition plays an important role in the intestinal absorption of nutrients. However, reports are not consistent whether intestinal enzymes are decreased in the presence of malnutrition. It is also not clear whether simultaneous presence of malnutrition and infection adds to the problem of malabsorption of nutrients. The aim of the present study was to determine intestinal functions in terms of concentrations of disaccharidase enzymes during diarrhoea and protein energy malnutrition. METHODS: Concentrations of three disaccharidase enzymes, namely maltase, sucrase and lactase were measured in nine energy-restricted and five control rabbits during diarrhoea induced by rabbit diarrhoeagenic Escherichia coli (RDEC-1). Malnutrition was achieved in the rabbit model by feeding the animals for 30 days with half the amount of food fed to well-nourished control rabbits. Both the energy-restricted and the control groups were challenged by RDEC-1. Diarrhoea occurred on day 1-7 after administration of the strain. After onset of diarrhoea, both groups of rabbits were sacrificed and their intestinal mucosa was examined to determine the concentration of lactase, maltase and sucrase. RESULTS: The energy-restricted animals and controls did not differ significantly for concentrations (units/mg proteins) of lactase (0.65 +/- 0.28 vs 0.56 +/- 0.17 ), maltase (6.20 +/- 2.70 vs 6.47 +/- 1.90) and sucrase (5.42 +/- 2.30 vs 5.13 +/- 1.40) measured during acute infectious diarrhoea. INTERPRETATION & CONCLUSION: The results suggested that the enzymatic functions of the intestinal brush border were not statistically different during diarrhoea among malnourished rabbits compared with their well-nourished counterparts.

Urinary retinol excretion in children with acute watery diarrhoea.

Children with diarrhoea due to rotavirus infection excrete retinol in urine. This study aimed at demonstrating the extent and mechanism of urinary retinol excretion in children with acute watery diarrhoea caused by pathogens other than rotavirus. Thirty-two children, aged five months to five years, hospitalized with watery diarrhoea predominantly due to enterotoxigenic Escherichia coli in Bangladesh, were studied. Their serum retinol and retinol-binding protein (RBP) were low at admission and increased significantly after recovery from illness. The mean hospital stay of these patients was four days. Forty-seven percent of the children excreted retinol in urine on day 1, and about 38% continued excreting retinol on day 3. The estimated urinary retinol loss of 3.44 micromol for the illness episode represented more than 40% of liver retinol reserve (8.25 micromol) in malnourished children. A conservative estimate of the loss would represent at least 20% of the liver reserve in relatively better-nourished children. Kidney tubular dysfunctions of increased RBP excretion significantly predicted urinary retinol excretion in children with watery diarrhoea.