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.