Pathways

Heparin, also known as unfractionated heparin (UFH), is a medication and naturally occurring glycosaminoglycan. Since heparins depend on the activity of antithrombin, they are considered anticoagulants. Specifically it is also used in the treatment of heart attacks and unstable angina. It is given intravenously or by injection under the skin.[2] Other uses for its anticoagulant properties include inside blood specimen test tubes and kidney dialysis machines. Heparin acts as an anticoagulant, preventing the formation of clots and extension of existing clots within the blood. While heparin itself does not break down clots that have already formed (unlike tissue plasminogen activator), it allows the body's natural clot lysis mechanisms to work normally to break down clots that have formed. Heparin is usually stored within the secretory granules of mast cells and released only into the vasculature at sites of tissue injury. Heparin binds to the enzyme inhibitor antithrombin III (AT), causing a conformational change that results in its activation through an increase in the flexibility of its reactive site loop. The activated AT then inactivates thrombin, factor Xa and other proteases. The rate of inactivation of these proteases by AT can increase by up to 1000-fold due to the binding of heparin. The conformational change in AT on heparin-binding mediates its inhibition of factor Xa. For thrombin inhibition, however, thrombin must also bind to the heparin polymer at a site proximal to the pentasaccharide. The highly negative charge density of heparin contributes to its very strong electrostatic interaction with thrombin. The formation of a ternary complex between AT, thrombin, and heparin results in the inactivation of thrombin. For this reason, heparin's activity against thrombin is size-dependent, with the ternary complex requiring at least 18 saccharide units for efficient formation.

Heparin, also known as unfractionated heparin (UFH), is a medication and naturally occurring glycosaminoglycan. Since heparins depend on the activity of antithrombin, they are considered anticoagulants. Specifically it is also used in the treatment of heart attacks and unstable angina. It is given intravenously or by injection under the skin.[2] Other uses for its anticoagulant properties include inside blood specimen test tubes and kidney dialysis machines. Heparin acts as an anticoagulant, preventing the formation of clots and extension of existing clots within the blood. While heparin itself does not break down clots that have already formed (unlike tissue plasminogen activator), it allows the body's natural clot lysis mechanisms to work normally to break down clots that have formed. Heparin is usually stored within the secretory granules of mast cells and released only into the vasculature at sites of tissue injury. Heparin binds to the enzyme inhibitor antithrombin III (AT), causing a conformational change that results in its activation through an increase in the flexibility of its reactive site loop. The activated AT then inactivates thrombin, factor Xa and other proteases. The rate of inactivation of these proteases by AT can increase by up to 1000-fold due to the binding of heparin. The conformational change in AT on heparin-binding mediates its inhibition of factor Xa. For thrombin inhibition, however, thrombin must also bind to the heparin polymer at a site proximal to the pentasaccharide. The highly negative charge density of heparin contributes to its very strong electrostatic interaction with thrombin. The formation of a ternary complex between AT, thrombin, and heparin results in the inactivation of thrombin. For this reason, heparin's activity against thrombin is size-dependent, with the ternary complex requiring at least 18 saccharide units for efficient formation.

Heparin, also known as unfractionated heparin (UFH), is a medication and naturally occurring glycosaminoglycan. Since heparins depend on the activity of antithrombin, they are considered anticoagulants. Specifically it is also used in the treatment of heart attacks and unstable angina. It is given intravenously or by injection under the skin.[2] Other uses for its anticoagulant properties include inside blood specimen test tubes and kidney dialysis machines. Heparin acts as an anticoagulant, preventing the formation of clots and extension of existing clots within the blood. While heparin itself does not break down clots that have already formed (unlike tissue plasminogen activator), it allows the body's natural clot lysis mechanisms to work normally to break down clots that have formed. Heparin is usually stored within the secretory granules of mast cells and released only into the vasculature at sites of tissue injury. Heparin binds to the enzyme inhibitor antithrombin III (AT), causing a conformational change that results in its activation through an increase in the flexibility of its reactive site loop. The activated AT then inactivates thrombin, factor Xa and other proteases. The rate of inactivation of these proteases by AT can increase by up to 1000-fold due to the binding of heparin. The conformational change in AT on heparin-binding mediates its inhibition of factor Xa. For thrombin inhibition, however, thrombin must also bind to the heparin polymer at a site proximal to the pentasaccharide. The highly negative charge density of heparin contributes to its very strong electrostatic interaction with thrombin. The formation of a ternary complex between AT, thrombin, and heparin results in the inactivation of thrombin. For this reason, heparin's activity against thrombin is size-dependent, with the ternary complex requiring at least 18 saccharide units for efficient formation.

Heparin is a naturally occurring anticoagulant that has a weight ranging from 3000 to 30 000 Da. It acts by binding antithrombin III that goes on to inactivate factor Xa. Heparin is mainly used for the treatment of venous thrombosis and prevention of thrombosis and embolism following a post-op of cardiac surgery. It accelerates the neutralization of coagulation factors by antithrombin, inhibiting further clotting from occurring as well as any progression of current clots from forming. It is administered intravenously or subcutaneous injection as heparin cannot be taken orally due to the gastrointestinal tract being unable to absorb it. Heparin is eliminated mainly through filtration by the kidneys and a small percentage eliminated through the urine. It possesses a half-life of 1.5 hours and has a clearance rate of 0.43ml/kg/min. Some side effects include heparin-induced-thrombocytopenia caused by a loss in platelet count and the chance of a clot becoming dislodged and obstructing a blood vessel. Overdose of heparin can result in excessive bleeding, while some correlation has been made with therapeutic doses of heparin and osteoporosis. Osteoporosis induced by heparin is seen to be reversible once the heparin use has been discontinued.

Heparin (also named unfractionated heparin or Clexane) is an anticoagulant medication. The main mechanism of heparin is acting on increasing the rate of antithrombin-related neutralization of coagulation factors for certain activated type. More specifically, heparin will bind to the antithrombin III (AT) that make antithrombin III changing to its activated form. Activated antithrombin III will inactive prothrombin and factor Xa (also other proteases).

Hereditary coproporphyria (HCP) is a rare inborn error of metabolism (IEM) which arises from a defective gene called CPOX. This gene is responsible for mitochondrial coproporphyrinogen-III oxidase. A defect in this enzyme results in accumulation of the porphyrin precursors porphobilinogen and 5-aminolevulinic acid; increase of fecal and urinary excreation of coproporphyrins. Symptoms for this condition vary substantially, with anything from reddish-purple urine, to bouts of acute abdominal and nerve pain, to episodes of photosensitive skin eruptions so extreme that the induced scratching often leads to permanent scarring. At the present time the condition has no cure. The following are some measures which are designed to help prevent and/or regulate the above and more symptoms: a diet which is high in carbohydrates and sugars, and a balanced lifestyle which abstains from alcohol and drug use.

Hereditary coproporphyria (HCP) is a rare inborn error of metabolism (IEM) which arises from a defective gene called CPOX. This gene is responsible for mitochondrial coproporphyrinogen-III oxidase. A defect in this enzyme results in accumulation of the porphyrin precursors porphobilinogen and 5-aminolevulinic acid; increase of fecal and urinary excreation of coproporphyrins. Symptoms for this condition vary substantially, with anything from reddish-purple urine, to bouts of acute abdominal and nerve pain, to episodes of photosensitive skin eruptions so extreme that the induced scratching often leads to permanent scarring. At the present time the condition has no cure. The following are some measures which are designed to help prevent and/or regulate the above and more symptoms: a diet which is high in carbohydrates and sugars, and a balanced lifestyle which abstains from alcohol and drug use.

Hereditary coproporphyria (HCP) is a rare inborn error of metabolism (IEM) which arises from a defective gene called CPOX. This gene is responsible for mitochondrial coproporphyrinogen-III oxidase. A defect in this enzyme results in accumulation of the porphyrin precursors porphobilinogen and 5-aminolevulinic acid; increase of fecal and urinary excreation of coproporphyrins. Symptoms for this condition vary substantially, with anything from reddish-purple urine, to bouts of acute abdominal and nerve pain, to episodes of photosensitive skin eruptions so extreme that the induced scratching often leads to permanent scarring. At the present time the condition has no cure. The following are some measures which are designed to help prevent and/or regulate the above and more symptoms: a diet which is high in carbohydrates and sugars, and a balanced lifestyle which abstains from alcohol and drug use.