ACTH and plasma corticosteroid levels in young calves.

1. Plasma sodium, potassium, aldosterone and cortisol levels were measured in seven 11-day-old calves after ACTH infusion and in five control animals. 2. During the 24 h following ACTH infusion the concentration of sodium and potassium in plasma and urine showed no significant variation either in treated or in control calves. 3. ACTH infusion induced a significant increase in plasma cortisol levels, which did not appear in control calves. Plasma aldosterone levels did not vary significantly in treated or in control calves.