Cortisol

Examples of Cortisol in the following topics:

• The Endocrine System and Stress

  • The ACTH acts on the adrenal cortex, which produces steroids—in humans, primarily the steroid cortisol.
  • In the process described above, the HPA axis ultimately produces cortisol.
  • Stressors that are uncontrollable, threaten physical integrity, or involve trauma tend to have a high, flat profile of cortisol release (with lower-than-normal levels of cortisol in the morning and higher-than-normal levels in the evening) resulting in a high overall level of daily cortisol release.
  • On the other hand, controllable stressors tend to produce higher-than-normal morning cortisol.
  • Children who were stressed prenatally may show altered cortisol rhythms.

• Stress and Disease

  • Furthermore, it has been shown that cortisol inhibits memory retrieval for already stored information.
  • The negative feedback of cortisol to the hypothalamus, pituitary, and immune systems is impaired.
  • This leads to a continual activation of the HPA axis and excess cortisol release.
  • Excessive cortisol release also has a negative impact on heart health.
  • High levels of cortisol correlate with an increased risk of heart disease.

• Aging and the Endocrine System

  • Three hormone axes are affected by aging: growth hormone/insulin-like growth factor I, cortisol/dehydroepiandrosterone, and testoterone/estradiol.
  • Another hormone axis that changes with aging is the cortisol/DHEA axis.
  • Two adrenal hormones, DHEA and cortisol have opposing effects on immune system function with DHEA generally enhancing immunity and cortisol suppressing it.
  • Cortisol on the other hand remains relatively unchanged with aging, causing an imbalance in hormone levels and thus altered immune function.
  • Glucocorticoids (GCs) such as cortisol also respond to ACTH and are released from the adrenal glands.

• Stress and Immunity

  • For example, expression of IL-1 IFN-gamma and TNF-alpha from immune cells are all inhibited by cortisol, while cytokines that control helper T-cell activity are increased.
  • Normally, stress responses are beneficial for the body, provided they are moderate and cortisol returns to normal levels after the stressful situation ends.
  • Cushing's syndrome is a chronic disease caused by persistent and excessive cortisol levels (from stress and often tumors that secrete cortisol).
  • Over time, immune cells may become desensitized to cortisol and express fewer cortisol receptors, so chronic inflammation can develop as the anti-inflammatory effect of cortisol is weakened.
  • Exercise relieves stress through endorphins, which have an inhibitory effect on cortisol secretion.

• Congenital Adrenal Hyperplasia

  • Congenital adrenal hyperplasia refers to an autosomal recessive disease caused by mutated genes for enzymes that produce cortisol from cholesterol.
  • Cortisol is an adrenal steroid hormone that is required for normal endocrine function.
  • Poor cortisol production is a hallmark of most forms of CAH.
  • Cortisol deficiency in CAH is usually partial and not the most serious problem for an affected person.
  • Synthesis of cortisol shares steps with synthesis of mineralocorticoids such as aldosterone, androgens such as testosterone, and estrogens such as estradiol.

• How Stress Impacts our Health

  • Sustained or chronic stress, in particular, leads to elevated hormones such as cortisol, the "stress hormone," and reduced serotonin and other neurotransmitters in the brain, including dopamine, which has been linked to depression.
  • Cortisol, also known as the "stress hormone", plays an integral role in our body's reaction to stress.
  • The hypothalamic-pituitary-adrenocortical system reacts within a person's brain, and it releases the hormone cortisol from the adrenal glad when one is exposed to a stressor.
  • Cortisol is most likely to be activated when a person is placed in a situation to be socially judged or evaluated, therefore under extreme levels of stress.
  • Higher and more prolonged levels of cortisol in the bloodstream are found with those suffering from chronic stress.

• Adrenal Cortex

  • Zona fasciculata is the layer, situated between the glomerulosa and reticularis, this layer is responsible for producing glucocorticoids, such as 11-deoxycorticosterone, corticosterone, and cortisol in humans.
  • Cortisol enhances the activity of other hormones including glucagon and catecholamines.
  • The primary glucocorticoid released by the adrenal gland in the human is cortisol and corticosterone in many other animals.
  • Upon binding to its target, cortisol enhances metabolism in several ways:

• Adrenal Gland Disorders

  • Adrenal insufficiency is a condition in which the adrenal glands do not produce adequate amounts of cortisol and/or aldosterone.
  • Adrenal insufficiency is a condition in which the adrenal glands, located above the kidneys , do not produce adequate amounts of steroid hormones, primarily cortisol, but may also include impaired aldosterone production which regulates sodium, potassium, and water retention.

• The Stress Response

  • ACTH acts on the adrenal cortices that produce glucocorticoid hormones, like cortisol, which is a stress hormone that exerts many effects throughout the body.
  • In the brain cortisol acts on both mineral corticoid and glucocorticoid receptors that are expressed by many different types of neurons.
  • ACTH is then transported through the circulatory system to the adrenal cortex where it promotes the biosynthesis of corticosteroids like cortisol and cholesterol.

• Steroids

  • Cholesterol also plays a role in synthesizing the steroid hormones aldosterone, which is used for osmoregulation, and cortisol, which plays a role in metabolism.
  • Steroids, such as cholesterol and cortisol, are composed of four fused hydrocarbon rings.