[Modifying effects of host factors in cadmium toxicity: species, sex, and age differences in mice]

Experiments were conducted with a view to studying how the factors on the side of the mouse would affect the toxicity of cadmium (Cd) in the acute exposure to it. The factors studied were strain, sex, age in days and the interaction among these. So far these factors have been studied independently. But it is suspected that they are affecting each other, so a simultaneous exploration was attempted in the present study as to the effects of these factors on the Cd accumulation in various organs. The results obtained were as follows: LD50 in acute Cd poisoning tended to be higher in C57BL/6 than in CF#1. Between the sexes it was higher in males than in females. As for the age of the mouse, the LD50 was higher in those aged 40 days and 80 days than in those 20-day- and 150-day-old. Changes in the body weight in acute Cd poisoning were analyzed by obtaining the variance for each factor. As a result a significant difference in the body weight change was revealed between the sexes, strains and ages of the animals and it was indicated that these factors modified the body weight changes in Cd poisoning. Cd concentration in the liver significantly differed among the strains and age groups. In the kidney the Cd concentration had a significant difference among the strains, sexes, ages in days, and interaction between the strain and age, suggesting that these factors might affect the Cd accumulation in the organs. The rate of Cd accumulated against the amount administered (accumulation rate) was studied in each of the organs. In the liver the accumulation rate was significantly affected by the age in days, and the interactions between strain and sex, strain and age, and sex and age, indicating that the modification occurred chiefly through the interactions among the factors. In the kidney the difference in the accumulation rate was attributed to strain, sex, and age in days, indicating that these factors affected the accumulation independently. From these results it was suggested that such factors as strain, sex and age in days affected directly or indirectly the manifestation of toxicity and accumulation of cadmium in the various organs to different degrees.