Normal, High, and Low Testosterone Levels

Testosterone Levels are helpful in evaluating abnormalities with sex characteristics. Testosterone Levels are also helpful in diagnosing precocious puberty, virilizing syndromes in the female, and infertility in the male. Testosterone Levels may also be used as a tumor marker for rare tumors of the ovary and testicle.   Androgens include Dehydroepiandrosterone (DHEA), androstenedione, and testosterone. […]
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Androstenedione, Dehydroepiandrosterone, and Dehydroepiandrosterone Sulfate

Androstenedione (AD), Dehydroepiandrosterone (DHEA), and Dehydroepiandrosterone Sulfate ester (DHEA S) are known as Androstenediones (ADs). Androstenediones are precursors of Testosterone and Estrone. Androstenediones and are made in the gonads and the adrenal gland. Adrenocorticotropic Hormone (ACTH) stimulates the adrenal secretion of Androstenediones. The ADs are often elevated in cases of hirsutism and virilization.
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Aldosterone

Aldosterone is  a hormone secreted by the adrenal cortex. Aldosterone is a potent mineralocorticoid. Production of Aldosterone is regulated primarily by the renin-angiotensin system. This system works as follows: a decreased effective renal blood flow triggers pressure-sensitive renal glomerular elements to release renin. The renin then stimulates the liver to secrete angiotensin I, which is converted […]
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Dexamethasone Suppression Test

Dexamethasone Suppression Test is based on pituitary Adrenocorticotropic Hormone (ACTH) secretion being dependent on the plasma cortisol feedback mechanism. When blood Cortisol Levels increase, the production of ACTH is suppressed. And vice versa, when blood Cortisol Levels decrease, the production of ACTH is stimulated. Dexamethasone is a synthetic steroid which suppress ACTH secretion the same way to […]
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Cortisol Levels in Blood

Cortisol Levels in Blood are measured for patients who are suspected to have Hyperfunctioning or Hypofunctioning Adrenal Glands. There is an elaborate feedback mechanism for cortisol coordinates the function of the hypothalamus, pituitary gland, and adrenal glands. When Corticotropin-releasing Hormone (CRH) is produced in the hypothalamus, it stimulates the production of Adrenocorticotropic Hormone (ACTH) in […]
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ACTH Stimulation with Metyrapone

Metyrapone (Metopirone) is a potent blocker of an enzyme involved in cortisol production. Cortisol production is therefore reduced. When this drug is given, the resulting decrease in cortisol production should stimulate pituitary secretion of Adrenocorticotropic Hormone (ACTH) by way of a negative-feedback mechanism. Cortisol itself cannot be synthesized because of the metyrapone inhibition at the […]
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ACTH Stimulation Test

Adrenocorticotropic Hormone Stimulation (ACTH Stimulation Test) is performed on patients found to have adrenal insufficiency. An increase in plasma cortisol levels after the infusion of an ACTH-like drug indicates that the adrenal gland is normal and capable of functioning if stimulated. In that case the cause of adrenal insufficiency would lie within the pituitary gland […]
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Adrenocorticotropic Hormone

Adrenocorticotropic Hormone (ACTH) is a tropic hormone produced by the anterior pituitary gland. There is an elaborate feedback mechanism for cortisol coordinates the function of the hypothalamus, pituitary gland, and adrenal glands. Adrenocorticotropic Hormone is an important aspect of this mechanism. Corticotropin-releasing hormone (CRH) is made in the hypothalamus. This stimulates Adrenocorticotropic Hormone production in the […]
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