Biomaterial Database

Prostaglandin endoperoxides and thromboxanes: role in platelets and in vascular and respiratory smooth muscle. 1976

B Samuelsson

1. Two groups of unstable (t 1/2 = 5 min) endoperoxides, PGG and PGH compounds, have been isolated and shown to be precursors of the prostaglandins. 2. A new group of compounds (thromboxanes) derived from the endoperoxides has been discovered. Thromboxanes have so far been found in platelets, leucocytes, lung tissue, spleen, kidney and umbilical artery. In platelets the thromboxane constitute the major products derived from the endoperoxides. 3. A highly unstable (t 1/2 = 30-40 s) intermediate, thromboxane A2, between the endoperoxides and thromboxane B2 has been detected. Structural work indicates that it has a bicyclic oxaneoxetane structure. 4. Thromboxane A2 induces platelet aggregation and causes contraction of the isolated rabbit aorta. Rabbit aorta contracting substance (RCS) discovered by PIPER and VANE consists mainly of thromboxane A2 and to some extent of the endoperoxides PGG2 and PGH2. 5. Endoperoxides and thromboxanes are essential for platelet aggregation. Platelet cyclo-oxygenase deficiency gives rise to a hemostatic defect due to an abnormal release mechanism. 6. The endoperoxides have unique actions on vascular and air-way smooth muscle. The effects are not due to conversion to the stable prostaglandins (PGE, PGF etc). 7. The biologically active compounds formed from polyunsaturated fatty acids via the cyclo-oxygenase catalyzed pathway can be divided into three groups depending on the stability, viz. the stable prostaglandins (PGE etc.), the endoperoxides (PGG and PGH) and the thromboxanes.

UI	MeSH Term	Description	Entries
D009119	Muscle Contraction	A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments.	Inotropism,Muscular Contraction,Contraction, Muscle,Contraction, Muscular,Contractions, Muscle,Contractions, Muscular,Inotropisms,Muscle Contractions,Muscular Contractions
D009130	Muscle, Smooth	Unstriated and unstriped muscle, one of the muscles of the internal organs, blood vessels, hair follicles, etc. Contractile elements are elongated, usually spindle-shaped cells with centrally located nuclei. Smooth muscle fibers are bound together into sheets or bundles by reticular fibers and frequently elastic nets are also abundant. (From Stedman, 25th ed)	Muscle, Involuntary,Smooth Muscle,Involuntary Muscle,Involuntary Muscles,Muscles, Involuntary,Muscles, Smooth,Smooth Muscles
D010545	Peroxides	A group of compounds that contain a bivalent O-O group, i.e., the oxygen atoms are univalent. They can either be inorganic or organic in nature. Such compounds release atomic (nascent) oxygen readily. Thus they are strong oxidizing agents and fire hazards when in contact with combustible materials, especially under high-temperature conditions. The chief industrial uses of peroxides are as oxidizing agents, bleaching agents, and initiators of polymerization. (From Hawley's Condensed Chemical Dictionary, 11th ed)	Peroxide
D010974	Platelet Aggregation	The attachment of PLATELETS to one another. This clumping together can be induced by a number of agents (e.g., THROMBIN; COLLAGEN) and is part of the mechanism leading to the formation of a THROMBUS.	Aggregation, Platelet
D011453	Prostaglandins	A group of compounds derived from unsaturated 20-carbon fatty acids, primarily arachidonic acid, via the cyclooxygenase pathway. They are extremely potent mediators of a diverse group of physiological processes.	Prostaglandin,Prostanoid,Prostanoids
D011460	Prostaglandins F	(9 alpha,11 alpha,13E,15S)-9,11,15-Trihydroxyprost-13-en-1-oic acid (PGF(1 alpha)); (5Z,9 alpha,11,alpha,13E,15S)-9,11,15-trihydroxyprosta-5,13-dien-1-oic acid (PGF(2 alpha)); (5Z,9 alpha,11 alpha,13E,15S,17Z)-9,11,15-trihydroxyprosta-5,13,17-trien-1-oic acid (PGF(3 alpha)). A family of prostaglandins that includes three of the six naturally occurring prostaglandins. All naturally occurring PGF have an alpha configuration at the 9-carbon position. They stimulate uterine and bronchial smooth muscle and are often used as oxytocics.	PGF
D011817	Rabbits	A burrowing plant-eating mammal with hind limbs that are longer than its fore limbs. It belongs to the family Leporidae of the order Lagomorpha, and in contrast to hares, possesses 22 instead of 24 pairs of chromosomes.	Belgian Hare,New Zealand Rabbit,New Zealand Rabbits,New Zealand White Rabbit,Rabbit,Rabbit, Domestic,Chinchilla Rabbits,NZW Rabbits,New Zealand White Rabbits,Oryctolagus cuniculus,Chinchilla Rabbit,Domestic Rabbit,Domestic Rabbits,Hare, Belgian,NZW Rabbit,Rabbit, Chinchilla,Rabbit, NZW,Rabbit, New Zealand,Rabbits, Chinchilla,Rabbits, Domestic,Rabbits, NZW,Rabbits, New Zealand,Zealand Rabbit, New,Zealand Rabbits, New,cuniculus, Oryctolagus
D001952	Bridged-Ring Compounds	Cyclic hydrocarbons that contain multiple rings which share one or more bridgehead connections.	Bridged Compounds,Bridged Ring Compounds
D002621	Chemistry	A basic science concerned with the composition, structure, and properties of matter; and the reactions that occur between substances and the associated energy exchange.
D006168	Guinea Pigs	A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.	Cavia,Cavia porcellus,Guinea Pig,Pig, Guinea,Pigs, Guinea