The cortisol concentration in plasma of newborn piglets and after ACTH loading]

In plasma of newborn piglets 12.6 +/- 2.9 mug cortisol/100 ml was estimated radioimmunologically. During the first 24 hours of life the concentration decreases to 1/3 of the starting level. After application of 5 IU ACTH/kg body weight, there was in newborn as in 5-day-old piglets an increase in the concentration of cortisol, while an influence on the level of glucose in plasma could not be detected in 0-day-old animals.