The effect of alpha-chymotrypsin inhibitor from Ascaris lumbricoides suum on chick embryos

It has been found that alpha-chymotrypsin inhibitor isolated from Ascaris lumbricoides suum acts embryotoxically on the Leghorn chicken embryo. An increase in embryo mortality with increasing dose of the inhibitor has been observed after its administration into the yolk sac on day 4, 8 or 13 of incubation. There is a linear interrelationship between the logarithm of the dose of alpha-chymotrypsin inhibitor and the mortality of chickens. The LD50 values foralpha-chymotrypsin inhibitor increased for injections performed at later stages of embryo development. A significant decrease of mean mass of chicks injected with alpha-chymotrypsin inhibitor in comparison with control groups was observed. There was a more frequent occurrence of developmental abnormalities and pathological changes in groups of hatched chicks which received the Ascaris inhibitor.