anti-diuretic hormone

Examples of anti-diuretic hormone in the following topics:

• Regulation of Urine Concentration and Volume

  • Antidiuretic hormone (ADH) is produced by the pituitary gland to control the amount of water that is reabsorbed through the collecting ducts.
  • There are a few complex systems involved in regulating blood volume and urine production, such as the intricate renin–angiotensin system, and the simpler anti-diuretic hormone (ADH) feedback system.
  • An anti-diruetic is a substance that decreases urine volume, and ADH is the primary example of it within the body.
  • Many substances can act as diuretics, albeit with different mechanisms.
  • Many medications are diuretics because they inhibit the ATPase pumps, thus slowing water reabsorption further.

• Overview of the Pituitary Gland

  • The pituitary gland is connected to the hypothalamus and secretes nine hormones that regulate body homeostasis.
  • The pituitary gland secretes hormones that regulate homeostasis.
  • The anterior pituitary receives signaling molecules from the hypothalamus, and in response, synthesizes and secretes seven important hormones including thyroid-stimulating hormone and growth hormone.
  • The posterior pituitary does not produce any hormones of its own, rather, it stores and secretes two hormones made in the hypothalamus—oxytocin and anti-diuretic hormone.

• Other Hormonal Controls for Osmoregulation

  • Angiotensin II also triggers the release of anti-diuretic hormone (ADH) from the hypothalamus, leading to water retention in the kidneys.
  • Mineralocorticoids are hormones synthesized by the adrenal cortex that affect osmotic balance.
  • ANP affects salt release; because water passively follows salt to maintain osmotic balance, it also has a diuretic effect.
  • ANP also prevents sodium reabsorption by the renal tubules, decreasing water reabsorption (thus acting as a diuretic) and lowering blood pressure.
  • The hormone ANP has antagonistic effects.

• Regulation of Water Output

  • The hormones ADH (anti-diuretic hormone, also known as vasopressin) and aldosterone, a hormone created by the renin-angiotensin system play a major role in this.
  • If the body is becoming fluid-deficient, there will be an increase in the secretion of these hormones, causing water to be retained by the kidneys through increased tubular reabsorption and urine output to be reduced.
  • Conversely, if fluid levels are excessive, secretion of these hormones is suppressed, resulting in less retention of fluid by the kidneys and a subsequent increase in the volume of urine produced, due to reduced fluid retention.
  • Aldosterone is a steroid hormone (corticoid) produced at the end of the renin-angiotensin system.

• Water Content in the Body

  • Much of this regulation is mediated by hormones, including anti-diuretic hormone (ADH), renin, angiotensin II, aldosterone and atrial natriuretic peptide (ANP).
  • These hormones act as messengers between the kidneys and the hypothalamus, however the lungs, and heart are also involved in the secretion of some of these hormones, such as angiotensin converting enzyme and ANP respectively.

• Nitrogenous Waste in Terrestrial Animals: The Urea Cycle

  • This mechanism, controlled by an anti-diuretic hormone, allows the body to create hyperosmotic urine, which has a higher concentration of dissolved substances than the blood plasma.

• Production of Dilute and Concentrated Urine

  • The hormones ADH (Anti-diuretic hormone, also known as vasopressin) and aldosterone play a major role in this balance.
  • If the body becomes fluid deficient, there will be an increase in the secretion of these hormones, causing fluid to be retained by the kidneys and urine output to be reduced.
  • Thus, there will be an increase in the secretion of antidiuretic hormone that causes fluid to be retained by the kidneys and urine output to be reduced.
  • The system then stimulates zona glomerulosa of the adrenal cortex which, in turn, secretes the hormone aldosterone.
  • This hormone stimulates the reabsorption of sodium ions from distal tubules and collecting ducts.

• Nephron, Parts, and Histology

  • It is regulated by the neuroendocrine system by hormones such as antidiuretic hormone, aldosterone, and parathyroid hormone.
  • However, anti-diuretic hormone (secreted from the pituitary gland as a part of homeostasis) will act on the distal convoluted tubule to increase the permeability of the tubule to water to increase water reabsorption.
  • Many other hormones will induce other important changes in the distal convoluted tubule that fulfill the other homeostatic functions of the kidney.
  • The collecting duct is similar in function to the distal convoluted tubule and generally responds the same way to the same hormone stimuli.
  • The osmolarity of fluid through the distal tubule and collecting duct is highly variable depending on hormone stimulus.

• Diuretics

  • There are several categories of diuretics.
  • The antihypertensive actions of some diuretics (thiazides and loop diuretics in particular) are independent of their diuretic effect.
  • Loop diuretics have this ability, and are therefore often synonymous with high ceiling diuretics.
  • The short-term anti-hypertensive action is based on the fact that thiazides decrease preload, decreasing blood pressure.
  • Chemically, diuretics are a diverse group of compounds that either stimulate or inhibit various hormones that naturally occur in the body to regulate urine production by the kidneys.

• Synthetic Antimicrobial Drugs

  • Synthetic agents include: sulphonamides, cotrimoxazole, quinolones, anti-virals, anti-fungals, anti-cancer drugs, anti-malarials, anti-tuberculosis drugs, anti-leprotics, and anti-protozoals.
  • The sulfonylureas and thiazide diuretics are newer drug groups based on the antibacterial sulfonamides.
  • The sulfonamide chemical moiety is also present in other medications that are not antimicrobials, including thiazide diuretics (including hydrochlorothiazide, metolazone, and indapamide, among others), loop diuretics (including furosemide, bumetanide, and torsemide), sulfonylureas (including glipizide, glyburide, among others), and some COX-2 inhibitors (e.g., celecoxib), and acetazolamide.