ADH
Antidiuretic hormone, or vasopressin, is a hormone that is primarily used to retain water in the body and constrict blood vessels. It is produced in the hypothalamus gland of the brain and then it is stored in and released from the posterior pituitary gland. ADH is a nonapeptide- 9 amino acids- The first six, tyrosinase, phenylalanine, 2 cysteines, aspartic acid, and glutamine, form a ring structure joined by disulfide bonds. The last three- proline, arginine, and glycine- form a string-like structure stemming from the ring. ADH follows a simple neurohormone pathway: first neurons in the hypothalamus gland synthesize ADH and send it to the posterior pituitary gland. Then, osmoreceptors are stimulated by plasma osmolarity, the regulation of solute concentration in blood. This means that osmoreceptors react to hypertonic blood concentration (too high) then stimulates the posterior pituitary gland which then secretes the ADH into the blood stream, and then goes and targets the effectors: the kidneys, the sweat glands, and blood vessels. At the kidneys, the primary effector, ADH binds to complementary receptors on the surface of the plasma membrane, stimulating a series of enzymes called reactions, which then produce an enzyme that then causes water to travel around and fuse with the plasma membrane through osmosis, which is how the body retains water. At the sweat glands, ADH binds to receptors that cause the glands to secrete less sweat. At the blood vessels, ADH binds to receptors that cause them to constrict so that the flow of blood is restricted or decreased. Thus, ADH is water soluble because it dissolves into the blood stream and into the water of the blood. Because it is water soluble, ADH is polar as opposed to being lipid soluble, which would make it nonpolar. ADH is a negative feedback mechanism because it can decrease blood levels and increase water levels when stimulated to balance the levels. To sum it up, ADH retains water and restricts blood flow when blood concentration is too high and water concentration is too low.
http://arbl.cvmbs.colostate.edu/hbooks/pathphys/endocrine/hypopit/adh.html
https://bsd-co-fc.beaverton.k12.or.us/~Kirk_Soule/Endocrine_Pathways.pdf
https://docs.google.com/file/d/0ByEdJ0zBzNIEVDZpNURnWHBJdGs/edit
https://bsd-co-fc.beaverton.k12.or.us/~Kirk_Soule/Endocrine_Pathways.pdf
https://docs.google.com/file/d/0ByEdJ0zBzNIEVDZpNURnWHBJdGs/edit
