Secretion rates of cortisol and aldosterone precursors in various forms of congenital adrenal hyperplasia.

Abstract

Using a previously described method for the simultaneous determination of the secretion rates of cortisol and aldosterone precursors, the specific enzyme deficiency in various form? of congenital adrenal hyperplasia was elucidated. Secretion rates of cortisol (F), 11-desoxycortisol (S), corticosterone (B), 11-desoxycorticosterone (DOC) and aldosterone (aldo) were determined in 10 normal subjects, 2 children with simple virilizing adrenal hyperplasia (21-hydroxylase defect) and 1 child with hypertensive virilizing adrenal hyperplasia (11-hydroxylase defect) under the following conditions: normal, low and high sodium (Na) diets, administration of metyrapone, dexamethasone and intravenous ACTH. The mean daily normal secretion rates were: F—7.5 mg/m2; S—0.26 mg/m2; B—2.2 mg/m2; DOC—0.055 mg/m2; aldo—0.13 mg/m2. Changes in dietary Na altered only aldo secretion. ACTH administration raised B and F secretion significantly. Metyrapone increased S and DOC secretion more than ACTH but decreased B, F and aldo secretion. In 21- hydroxylase defect the secretion rates of B, F, DOC and S did not increase appropriately with ACTH and aldo secretion showed a blunted increase with low Na diet. Secretion of B and F was below normal under all conditions. In the 11-hydroxylase defect the secretion rates of B and F were very low and did not increase with ACTH, while the secretion rates of DOC and S were 100 times normal and increased further with ACTH and metyrapone. Aldosterone secretion was very low and did not increase with Na deprivation. Results confirmed a deficiency of 21-hydroxylase in the simple form and a deficiency of 11-hydroxylase in the hypertensive form of adrenal hyperplasia.