Characterization of adrenocorticotropin secretion in a patient with 17 alpha-hydroxylase deficiency.
17 alpha-Hydroxylase deficiency (17-OHDS) is a peculiar type of adrenal insufficiency because of elevated corticosterone (B) production. Episodic and circadian ACTH secretion and the responses to ovine CRH and metyrapone were examined in a female with 17-OHDS under conditions of normal sodium (NSI) and low sodium (LSI) intake. Plasma ACTH and B were higher on LSI than on NSI (mean +/- SD: ACTH, 58 +/- 20 vs. 33 +/- 14 pmol/L; B, 508 +/- 107 vs. 381 +/- 69 nmol/L). ACTH pulses were concomitant with or followed by B pulses. An increase in the amplitude, but not the number, of ACTH and B pulses was found on LSI. Circadian ACTH and B rhythms persisted on LSI. Aldosterone levels were higher on LSI than on NSI. After metyrapone, plasma B decreased in the afternoon (NSI, 220 +/- 10; LSI, 275 +/- 35 nmol/L) and rose on the following morning. Plasma ACTH increased substantially on the following morning (NSI, 135 +/- 47; LSI, 307 +/- 77 pmol/L). The ACTH peak levels after ovine CRH increased after metyrapone administration. These data indicate that B may also have a negative feedback effect at the pituitary level. In all maneuvers, there were no changes in PRA, plasma sodium and potassium, or cortisol. We conclude that in 17-OHDS, in the absence of cortisol production, ACTH and B may interact to modulate the brain-pituitary-adrenocortical system.
Moreira
A C
AC
Department of Medicine, Faculty of Medicine, Ribeirão Preto SP, Brazil.
Leal
A M
AM
Castro
M
M
D000293:Adolescent; D000312:Adrenal Hyperplasia, Congenital / Q000097:blood / Q000201:enzymology*; D000324:Adrenocorticotropic Hormone / Q000097:blood* / Q000378:metabolism; D002940:Circadian Rhythm; D003346:Corticotropin-Releasing Hormone; D005260:Female; D006801:Humans; D008797:Metyrapone; D013250:Steroid Hydroxylases / Q000172:deficiency*
D000324:Adrenocorticotropic Hormone; D003346:Corticotropin-Releasing Hormone; D013250:Steroid Hydroxylases; D008797:Metyrapone