The distal convoluting tubule and the collecting duct.
Vasopressin (Antidiuretic Hormone). Vasopressin (arginine vasopressin, AVP; antidiuretic hormone, ADH) is a peptide hormone formed in the hypothalamus, then transported via axons to, and released from, the posterior pituitary into the blood. AVP has two principle sites of action: the kidney and blood vessels Anti-diuretic hormone acts to maintain blood pressure, blood volume and tissue water content by controlling the amount of water and hence the concentration of urine excreted by the kidney. Alternative names for anti-diuretic hormone Vasopressin; arginine vasopressin; AVP; ADH. What is anti-diuretic hormone? Anti-diuretic hormone is made by special nerve cells found in an area at the base of the brain known as the hypothalamus. The nerve cells transport the hormone down their nerve fibres (axons) to the pituitary gland where the hormone is released into the blood stream. Vasopressin is a peptide hormone that increases water permeability of the kidney's collecting duct and distal convoluted tubule by inducing translocation of aquaporin-CD water channels in the plasma membrane of collecting duct cells. Vasopressin regulates the body's retention of water by acting to increase water reabsorption in the kidney's collecting ducts, the tubules which receive the very dilute urine produced by the functional unit of the kidney, the nephrons. Antidiuretic hormone binds to receptors on cells in the collecting ducts of the kidney and promotes reabsorption of water back into the circulation. In the absense of antidiuretic hormone, the collecting ducts are virtually impermiable to water, and it flows out as urine. Physiologic Effects of Antidiuretic Hormone. Effects on the Kidney. The single most important effect of antidiuretic hormone is to conserve body water by reducing the loss of water in urine. A diuretic is an agent that increases the rate of urine formation. Vasopressin, also known as arginine vasopressin (AVP), antidiuretic hormone (ADH), or argipressin, is a neurohypophysial hormone found in most mammals. Its two primary functions are to retain water in the body and to constrict blood vessels. Vasopressin regulates the body's retention of water by acting to increase water reabsorption in the kidney's collecting ducts, the tubules which receive the very dilute urine produced by the functional unit of the kidney, the nephrons. That water concentrations are regulated by a hormone called ADH. That ADH effects the permeability of the distal convoluting tubule and the collecting duct. That aldosterone controls sodium concentrations in the blood. The Collecting Duct Hormones control the permeability of the walls of the collecting duct. If the walls are water-permeable, water leaves the ducts to pass into the hyperosmotic surroundings and concentrated urine is produced. If the ducts are impermeable to water the final urine will be less concentrated. Antidiuretic hormone stimulates water reabsorbtion by stimulating insertion of water channels or aquaporins into the membranes of kidney tubules. These channels transport solute-free water through tubular cells and back into blood, leading to a decrease in plasma osmolarity and an increase osmolarity of urine. Physiologic Effects of Antidiuretic Hormone. Effects on the Kidney. The single most important effect of antidiuretic hormone is to conserve body water by reducing the loss of water in urine. A diuretic is an agent that increases the rate of urine formation.
http://www.cvphysiology.com/Blood%20Pressure/BP016.htm http://www.yourhormones.info/hormones/antidiuretic_hormone.aspx https://en.wikipedia.org/wiki/Vasopressin http://arbl.cvmbs.colostate.edu/hbooks/pathphys/endocrine/hypopit/adh.html https://en.wikipedia.org/wiki/Vasopressin http://lichfield.org/ictscience_moodledata/2/Module_4/homeostasis/Hormonal_Control_of_Osmoregulation_Excretion.ppt http://arbl.cvmbs.colostate.edu/hbooks/pathphys/endocrine/hypopit/adh.html
antidiuretic hormone affects the permeability of