Hormonal regulation of renal function

By /

Hormonal regulation of renal function

ADH and water conservation

ADH is synthesised in the cell bodies of hypothalamic nuclei (supraoptic nuclei) and transported to nerve fibre endings in the posterior lobe of the pituitary where it is stored in the secretory granules.

Its release in the blood is controlled by osmoreceptors in the hypothalamus that are close to the supraoptic nuclei. It regulates water conservation. Increase in plasma osmolality stimulates osmoreceptors in the hypothalamus causing release of ADH which decreases the ECF volume. Fear and pain also causes release of ADH.

Aldosterone

Adrenal cortex regulates K+ and Na+ concentration. It acts on tubules causing Na+ reabsorption and K+ excretion. Aldosterone increases Na+ reabsorption from distal tubules by increasing Na+ transport protein; salt free diet causes increased aldosterone secretion resulting in increased Na reabsorption. 

Renin – Angiotensin system

Hormonal regulation of renal function - Renin - Angiotensin system
Renin – Angiotensin – Aldosterone system

Renin is activated by reduced circulating blood volume as in hemorrhage. Decreased sodium concentration in the distal convoluted tubule and sympathetic stimulation also causes release of renin.

Parathyroid hormone

Ca2+ and PO4 excretion in urine is regulated at the proximal tubule by the action of parathyroid and thyrocalcitonin from thyroid. Parathyroid hormone (PTH) causes decrease in PO4 reabsorption and increase in PO4 excretion in urine. PTH increases mobilisation of Ca2+ from bone and absorption from intes­tine resulting in increased plasma Ca2+ level and decreased Ca++ excretion.

Atrial natriuretic peptide

Myocardial cells of the atria release the ANP when the atria are stretched during high volume of blood. It has the following functions.

  1. Increases the GFR by causing vasodilatation of afferent arterioles and vasoconstriction of efferent arterioles.
  2. Inhibits angiotensin II stimulated absorption of Na+ and water in proximal tubules.
  3. Reduces water reabsorption in collecting tubules.
  4. Inhibits aldosterone release.
  5. Decreases the response of the collecting tubules and collecting ducts to ADH.

Local hormones

Erythropoietin produced from kidney regulates erythro­poiesis.

Renin is produced from kidney.

Prostaglandin from kidney acts as blood pressure lowering agents. PGE is natriuret­ic.

Scroll to Top