Thromboxane

• (5Z, 9α, 11α, 13E, 15S ) -epoxy -15 -9.11 hydroxythromboxa -5 ,13- dien-1- acid
• TXA2

Template: Infobox chemical / molecular formula search available

Thromboxane (or more precisely, thromboxane A2 or short TXA2 ) is a related to the prostaglandins biomolecule mainly in thrombocytes ( platelets) occurs and is named after them. It contains an oxane ring of five carbon and one oxygen atom. From the precursor arachidonic acid into prostaglandin H2 is formed by cyclooxygenase and peroxidase first. That finally, the thromboxane synthase ago thromboxane A2.

Properties

Thromboxane mediates its effects via the thromboxane receptor, a membrane- bound G protein-coupled receptor. The active thromboxane A2 is reduced to a half life of 30 seconds to the inactive metabolite thromboxane B2 in the body.

• Platelet aggregation: thromboxane is formed, among others, in platelets, where it is the prostaglandin mainly formed. It activates platelet aggregation via the thromboxane receptors on platelets and is an opponent of the anti-coagulant prostacyclin formed by the endothelium. Platelets contain only cyclooxygenase- 1 for prostaglandin formation. This is irrecoverably inoperable by acetylsalicylic acid and then can not be re- formed in platelets ( because they are seedless ). Therefore, these platelets are even after small doses of aspirin significantly reduced for the rest of their 8-12 days of life in the organism in their ability to aggregate.
• Smooth muscle: effects on thromboxane thromboxane receptors also a contraction of all the smooth muscle of blood vessels and airways.