QS Study

Steps of biosynthesis of the steroid or Adrenal Cortex Hormone

Steroids are transported through the bloodstream to the cells of various target organs where they carry out the regulation of a wide range of physiological functions. The adrenal cortex is a factory for steroid hormones. The hormones of the adrenal cortex are derivatives of cholesterol. The steroid hormones are synthesized primarily by Endocrine Glands such as the Adrenal Cortex and the Gonads (Ovary and Testes) and are then released into the blood circulation.

Innumerable steroids have been isolated from adrenal tissue, but the only steroids normally secreted in physiologically significant amounts are –

  1. Mineralocorticoids – Aldosterone is the most potent mineralocorticoid does not have any specific plasma transport protein. But it forms a very weak association with albumin.
  2. Glucocorticoids – They are an essential component of adaptation to “Severe stress”. Promote protein and RNA metabolism.
  3. Androgens (Dehydroepiandrosterone and Androstenedione) – It is a sympathomimetic amine which causes bronchodilation, vasoconstriction, CNS stimulation, and mydriasis. It has been used to arouse the heart in cardiac failure and its actions are mediated by adrenoceptors.

The main adrenal steroid hormones are synthesized in diverse areas of the adrenal cortex: glucocorticoids (particularly cortisol), androgens, and estrogens in the zona fasciculata and reticularis; and aldosterone in the zona glomerulosa.