Changes in Plasma Amino Acids during Development of X-irradiated Chick Embryos

Summary

1. Studies were made of the plasma amino acids of chick embryos from days 5–19 of development after x-irradiation with 600 r on the fourth day of incubation.

2. The levels of amino acids in the 6–8 day embryos decreased: this was a general effect and was not specific for any single amino acid.

3. The levels of amino acids in the 5 day and in the 9–19 day embryos increased: this, again, was a general effect and was not specific for any single amino acid. For days 9–12 the increase in free amino acids was statistically significant. No abnormally occurring amino acids were present.

4. It is believed that the responses of the embryos between 5 and 8 days may be peculiar to developing embryonate tissue, while the responses between 9 and 19 days indicate a basic metabolic disturbance and not one that is peculiar to embryonate tissue.

5. Possible relationships between this increase in free plasma amino acids following x-irradiation and the enhancement of the growth of rickettsial organisms by administration of x-irradiation are discussed.