renin

Examples of renin in the following topics:

• Long-Term Renal Regulation

  • Consistent and long-term control of blood pressure is determined by the renin-angiotensin system.
  • A key modulator of blood viscosity is the renin–angiotensin system (RAS) or the renin–angiotensin–aldosterone system (RAAS); a hormone system that regulates blood pressure and water balance.
  • When blood volume is low, juxtaglomerular cells in the kidneys secrete renin directly into circulation.
  • Plasma renin then carries out the conversion of angiotensinogen released by the liver to angiotensin I.
  • If the renin–angiotensin–aldosterone system is too active, blood pressure will be too high.

• Sodium Balance Regulation

  • Extra sodium is lost from the body by reducing the activity of the renin-angiotensin-aldosterone system which leads to increased sodium loss from the body.
  • A low renal perfusion pressure stimulates the release of renin, which forms angiotensin I which is converted to angiotensin II.
  • The perfusion pressure to the adrenal gland has little direct effect on aldosterone secretion and the low blood pressure operates to control aldosterone via the renin angiotensin system.
  • Regulation of sodium via the hormones renin, angiotensin, and aldosterone.

• Developmental Changes in Fluids

  • Hormonal mechanisms including the renin-angiotensin system, aldosterone, and vasopressin are involved in modifying fetal renal excretion, reabsorption of sodium and water, and regulation of vascular volume.
  • Overview of the renin-angiotensin system that regulates blood pressure and water (fluid) balance.

• Regulation of Water Output

  • A fluid-insufficiency causes a decreased perfusion of the juxtaglomerular apparatus in the kidneys, activating the renin-angiotensin system.
  • The activated renin-angiotensin system stimulates zona glomerulosa of the adrenal cortex, which in turn secretes hormone aldosterone.
  • Overview of the renin-angiotensin system that regulates blood pressure and water (fluid) balance.

• Nonrespiratory Air Movements

  • ACE converts angiotensin I into angiotensin II, which are two important hormones in the renin-angiotensin feedback loop of the renal system.
  • The Renin-Angiotensin System is dependent on ACE from the lungs to regulate blood pressure.

• Adrenal Cortex

  • The cortex is regulated by neuroendocrine hormones secreted by the pituitary gland which are under the control of the hypothalamus, as well as by the renin-angiotensin system.
  • Its secretion is regulated by the oligopeptide angiotensin II (angiotensin II is regulated by angiotensin I, which in turn is regulated by renin).

• Other Hormone-Producing Structures

  • The kidneys secrete a variety of hormones, including erythropoietin, and the enzyme renin.
  • Part of the renin-angiotensin-aldosterone system, renin is an enzyme involved in the regulation of aldosterone levels.

• Congestive Heart Failure

  • Reduced perfusion (blood flow) to the kidneys stimulates the release of renin – an enzyme that catalyzes the production of the potent vasopressor angiotensin .
  • Reduced perfusion (blood flow) to the kidneys stimulates the release of renin, an enzyme that catalyzes the production of the potent vasopressor angiotensin.

• Liver Function

  • The liver synthesizes angiotensinogen, a hormone that is responsible for raising the blood pressure when activated by renin, an enzyme that is released when the kidney senses low blood pressure.

• Overview of the Urinary System

  • Kidneys play a very large role in human osmoregulation by regulating the amount of water reabsorbed from glomerular filtrate in kidney tubules, which is controlled by hormones such as antidiuretic hormone (ADH), renin, aldosterone, and angiotensin I and II.
  • Besides ADH secretion, the renin-angiotensin feedback system is critically important to maintain blood volume and blood pressure homeostasis.