Effect of Protein on the Migration of Ancylostoma caninum Larvae in Mice

Recently, attention became more sharply focused on zoonotic larval nematode infections, particularly infections due to dog hookworm, Ancylostoma caninum and dog ascarid, Toxocara canis. In general, it has been known well that malnutrition and a protein free diet resulted in the increased susceptibility and the decreased acquired resistance to parasite. However, there was no report concerning the nutritional condition of the host and infectivity of a certain nematode larva. In ordet to elucidate the effect of protein in the diet on the larval migration in the organs and tissues of mice and on the fraction of gamma-globulin related closely with antibody response, an experiment was designed to follow the short-term course of infection of Ancylostoma caninum larva in mice fed with a standard diet(group 1), protein-free diet(group 2) and high protein diet(group 3). For the purpose, tissue digestion method using Baermann apparatus for the larval count and Gelman electrophoresis equipment for the measurement of gamma-globulin were applied. The results obtained from the present study are summarized as follows: 1) The range of average recovery rates of larva throughout the observation was 7~49% in group 1, 11~56% in group 2 and 6~44% in group 3, respectively. Significantly more larvae were detected and the larval migration preceeded more rapidly in group 2. 2) All the levels of total serum protein decreased soon after infection and the patterns continued up to the end of the experiment. It indicated that the compensatory power of the host was not able to maintain constant protein concentration. 3) The range of gamma-globulin fraction of serum protein after infection revealed 16.3~18.8%, a moderate increase in group 1, 17.5~19.3%, a pronounced increase in group 3, and 13.5~14.2%, a low degree of increase in group 2, respectively. Increase of gamma-globulin in group 1 and 3 were highly significant statistically to compare with that of group 2.