11-Deoxycortisol in mammals has limited glucocorticoid activity, but it is the direct precursor of the major mammalian glucocorticoid, cortisol. As a result, the level of 11-deoxycortisol is measured to diagnose impaired cortisol synthesis, to find out the enzyme deficiency that causes impairment along the pathway to cortisol, and to differentiate adrenal disorders. In
11β-hydroxylase deficiency, 11-deoxycortisol and
11-deoxycorticosterone levels increase, and excess of
11-deoxycorticosterone leads to
mineralocorticoid-based
hypertension (as opposed to
21-hydroxylase deficiency, in which patients have
low blood pressure from a lack of
mineralocorticoids). Low levels of cortisol can affect blood pressure by causing a decrease in sodium retention and volume expansion. This is because cortisol plays a role in regulating the balance of water and
electrolytes in the body. When cortisol levels are low, there is less sodium reabsorption by the kidneys, leading to increased excretion of sodium through urine. This ultimately reduces blood volume and lowers blood pressure. On the other hand, high levels of cortisol can also affect blood pressure by causing an increase in sodium retention and volume expansion. Cortisol-induced hypertension is accompanied by significant sodium retention, leading to an increase in extracellular fluid volume and exchangeable sodium. This results in an increase in blood volume and subsequently increases blood pressure. The underlying mechanisms for these effects involve various factors such as suppression of the nitric oxide system, alterations in vascular responsiveness to pressor agonists like adrenaline, increased cardiac output or stroke volume due to plasma volume expansion, and potential dysregulation of glucocorticoid receptors or
11β-hydroxylase enzyme activity. It's important to note that these mechanisms may be relevant not only for cortisol-induced hypertension but also for conditions such as
Cushing's syndrome (excess cortisol production), apparent mineralocorticoid excess (related to defects in
11β-hydroxylase enzymes),
licorice abuse (
glycyrrhetinic acid affecting
glycyrrhetinic acid receptor), chronic renal failure (prolonged half-life of cortisol due to reduced
11β-hydroxylase activity), and even essential hypertension where there may be abnormalities with
11β-hydroxylase activity or glucocorticoid receptor variations. Low levels of cortisol lead to reduced
vascular tone as cortisol helps maintain normal vascular tone by promoting vasoconstriction. Low levels of cortisol can lead to decreased vasoconstriction, resulting in relaxed blood vessels and lower overall blood pressure. Also, low cortisol levels lead to impaired fluid balance, as cortisol affects fluid balance by influencing sodium and water reabsorption in the kidneys. When cortisol levels are low, sodium absorption may be reduced, leading to increased excretion of sodium in the urine and subsequent lowering of blood volume and blood pressure. Additionally, low levels of cortisol cause a dysregulated renin-angiotensin system, as cortisol interacts with the renin-angiotensin system, which regulates blood pressure through vasoconstriction and fluid balance. Low cortisol levels can disrupt this system, leading to altered angiotensin production, reduced aldosterone secretion, and subsequently lower blood pressure. Conversely, high levels of cortisol lead to increased vascular tone, enhanced sodium retention, and increased sympathetic activity. Stress-induced release of high-level glucocorticoids such as cortisol activates the sympathetic nervous system (SNS). The SNS controls heart rate, cardiac output, and vasomotor tone, causing constriction, and thereby increasing peripheral arterial resistance, resulting in an increase in blood pressure. In
11β-hydroxylase deficiency, 11-deoxycortisol can also be converted to
androstenedione in a pathway that could explain the increase in androstenedione levels this condition. In
21-hydroxylase deficiency, 11-deoxycortisol levels are low. == History ==