Mild-to-moderate malnutrition and small intestine of young rhesus monkeys

The effect of severe malnutrition and protein deficiency on small intestine has been documented, but the literature on the effect of mild-to-moderate protein-energy malnutrition (PEM) on small intestine is scant. Mild-to-moderate PEM is most prevalent in India. Twenty-four young rhesus monkeys weighing 1.5-2.0 kg were divided into two groups, control and experimental. Mild-to-moderate PEM was induced in the experimental group by giving half of the required normal diet providing 2.42 g protein.kg-1.day-1 and 55 kcal.kg-1.day-1. Body weight, serum protein, and D-xylose were measured before starting the experiment, at PEM stage, and after rehabilitation. Experimental monkeys representing group I were killed after a 25-30% reduction in body weight along with control group 1 animals at 12 wk. The rest of the experimental animals were rehabilitated for another 10-12 wk and killed along with their respective controls (control group 2). Brush-border membrane vesicles were prepared from three parts of the small intestine. Viable vesicles were used for the uptake of [U-14C]L-proline. Alkaline phosphatase and enterokinase were also measured. Uptake of L-proline amino acid and the activity of both enzymes were found to be decreased significantly in the PEM group; a D-xylose test was abnormal. All animals recovered after rehabilitation. These results indicate that even mild-to-moderate malnutrition affects the absorptive and digestive capacity of the brush border of the small intestine, which reversed back on rehabilitation.