Summary of Synthesis of steroid hormones
The three major classes of steroid hormones are Glucocorticoids, Mineralocorticoids, and Sex hormones.
- Glucocorticoids include Cortisol
- Mineralocorticoids include Aldosterone
- Sex hormones include Androgens, Estrogens, and progestins
Steroid hormones are produced in the adrenal cortex and in peripheral tissues such as the gonads and placenta.
Steroid hormones are hydrophobic and are transported in the bloodstream by carrier proteins like albumin, corticosteroid binding globulin, and sex hormone binding protein.
Once inside the cell, steroid hormones bind to receptors in the cytoplasm or nucleus, leading to dimerization and binding to DNA to increase transcription of target genes.
Cholesterol is the precursor molecule for all steroid hormones, and its synthesis involves multiple steps and enzymes.
Cortisol is produced in the zona fasciculata, Aldosterone in the zona glomerulosa, and Androgens in the zona reticularis of the adrenal cortex.
Cortisol plays a role in stress response, glucose production, lipid metabolism, blood pressure regulation, immune suppression, and bone metabolism.
Aldosterone is involved in sodium reabsorption, water retention, and potassium secretion in the kidneys.
Androgens like DHEA and androstenedione are produced in the adrenal cortex and can be converted to testosterone or estradiol.
Steroid hormones are metabolized in the liver and excreted in the feces and urine.
Notable Quotes
— 04:21 — « The first step is the rate limiting step, catalyzed by an enzyme known as desmolase. »
— 07:47 — « Ultimately, cortisol stimulates the production and release of cortisol, the stress hormone. »
— 11:07 — « Low levels of sodium end up in the kidneys, stimulating the juxtaglomerular apparatus to release renin. »
— 13:22 — « Both the zona fasciculata and the zona reticularis can produce androgens, but predominantly androgens are produced in the zona reticularis. »
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Science and Nature