The main role of AVP is to regulate blood pressure. AVP is released when the body experiences nausea. The secretion of AVP is so powerful that it can increase the plasma level 20 to 500-fold without any changes in blood pressure or vomiting. AVP circulates as a free peptide and diffuses into the extracellular fluid space. It is metabolized by vasopressinase enzyme in the liver and kidneys.
Vasopressin is a naturally produced hormone in the human body, although the term “vasopressin” has other meanings. Vasopressin regulates the tonicity of body fluids, and is produced by neurons in the hypothalamus and supraoptic nuclei. It acts by increasing the vasoconstriction of blood vessels and reabsorption of solute-free water.
AVP plays a pivotal role in maintaining sodium balance in the body. This balance is important for physiologic regulation. It is transported by unique neurophysin, but is cleaved from it during transport to the kidneys. It is then stored as a free form in the cells of the kidney. AVP is also known as an antidiuretic hormone. It regulates the excretion of sodium in the urine and promotes water conservation.
AVP is a type of hormone that acts through the activation of Ca++ and cAMP. Both AVP and glucagon act by stimulating the activity of these two second messengers, although their actions may be additive. The receptors that bind to glucagon and AVP are different. So, AVP and glucagon may have different roles in the body. In addition to their different functions, both AVP and glucagon stimulate the cAMP signaling pathway in the liver.
Prohormones are a type of hormone that has multiple uses in the body. They are hormone precursors that signal the release of a mature hormone. In addition to its role as a surrogate marker, they can also be used as an indicator of insulin secretion. Various researchers have found copeptin to be an effective surrogate marker for AVP. It has a large role in determining the cause of cardiovascular disease and evaluating treatment options.
Another function of AVP is to regulate cholangiocyte proliferation. The V2 receptor is expressed in the bile ducts of mice and rats. It is found that the V2 receptor promotes biliary cyst proliferation. The V2 receptor may be responsible for the regulating of the proliferation rate in human cholangiocytes. In a rat model, AVP increases the levels of cAMP in human cholangiocytes.