Impact of Nippostrongylus brasiliensis (Nematoda) on the serum albumin and amino acid concentrations of rats fed adequate or protein-deficient diets

Abstract

Food intake, body weight changes, serum protein and amino acid concentrations were measured during the course of primary infections of Nippostrongylus brasiliensis in rats fed on either a 2% protein (casein) diet or a 16% protein diet (Oxoid 41 B). Total serum protein concentration declined from 77.84 +/- 5.35 mg/ml in uninfected well-nourished rats to 54 +/- 3.29 mg/ml in rats at 9 days post-infection (p.i.). A reduction from 47.80 +/- 2.78 to 40.38 +/- 5.62 mg/ml had occurred in protein-malnourished rats by day 6 p.i. The hypoproteinaemia was accompanied by significant hypoalbuminaemia in the protein-malnourished rats and concentrations fell from approximately 33 to 19 mg/ml at the time of peak infection. Six days after inoculation, a significant increase was detected in the concentration of serum amino acids in both well-nourished and protein-malnourished rats; the effect was more prolonged for non-essential than for essential amino acids. The results are discussed briefly in relation to recent work on the control of protein metabolism during malnutrition.