11-Deoxycorticosterone (DOC) measurement is useful in the investigation of hypertension, particularly hypertension associated with hypokalaemia when the patient does not receive diuretics, following a regular sodium diet.
Measurement of 11-deoxycorticosterone is also useful in girls with sex development abnormalities and hypertension.
DOC measurement is also recommended in all cases of increased blood cortisone.
11-Deoxycorticosterone (DOC) is synthesized from progesterone by the action of the enzyme 21-hydroxylase. DOC and corticosterone are produced in all three zones of the adrenal cortex, zona glomerulosa, zona fasciculata and zona reticularis. Only in the latter two, however, do the two steroids act as precursor molecules for aldosterone. Both DOC and corticosterone have mineralocorticoid activity but much less than aldosterone.
11-Deoxycorticosterone and corticosterone are produced and secreted under the stimulation of ACTH and in parallel with cortisol.
DOC circulates mainly in plasma bound to plasma proteins, 36% to CBG (corticosteroid-binding globulin or transcortin), and 60% to albumin.
DOC, like all steroids, is metabolized in the liver by successive reductions to a metabolite (THDOC) which is then conjugated to glucuronide and excreted in the urine.
Deficiency of 11-β Hydroxylase
This deficiency accounts for 5 to 8% of known cases of adrenal blockage. It affects both the composition of glucocorticoids and corticosteroids, while the biochemical pathway of androgens is unaffected. This results in increased secretion of adrenal androgens and precursors of cortisol and aldosterone, 11-deoxycortisol and 11-deoxycorticosterone (DOC), respectively. Pathophysiologically, the accumulation of DOC which has potent mineralocorticoid activity explains hypertension due to salt retention.
Deficiency of 17-α Hydroxylase (CYP17)
17a-hydroxylase deficiency is a rare cause of congenital adrenal hyperplasia. This deficiency is usually found in adolescence from hypertension, hypokalaemia, and hypogonadism. Hypogonadism occurs in girls with primary amenorrhea and the absence of secondary sex characteristics.
The boys present male pseudo-hermaphroditism with female external genitalia but uterus and fallopian tubes are absent. The testes are located intra-abdominally and contain hyperplastic Leydig cells. Regardless of gender, most patients have hypertension with hypokalaemia.