Biomaterial Database

Prostaglandins, oxygen tension and smooth muscle tone. 1972

A Eckenfels, and J R Vane

1. By using indomethacin to inhibit their intramural synthesis, we have investigated the contribution of prostaglandins to the maintenance of (a) the intrinsic tone of isolated smooth muscle preparations and (b) contractions produced by drugs or high oxygen concentration.2. When treated with indomethacin, the rat stomach strip and chick rectum preparation slowly relaxed, whether they were bathed in Krebs solution or blood. Although their sensitivity to added prostaglandin was somewhat enhanced, they became insensitive to changes in oxygen or glucose concentration. However, another smooth muscle preparation, the rat colon, was neither relaxed by indomethacin nor contracted by high oxygen concentration.3. These results support the hypothesis that intramural generation of prostaglandin maintains the tone of some smooth muscle preparations.4. Contractions of the guinea-pig isolated colon were induced by histamine. These contractions were normally well maintained but in Krebs solution lacking either oxygen or glucose, only the initial spike contraction remained. In the presence of indomethacin the histamine contraction was also poorly sustained, but maintenance was restored by a low concentration of prostaglandin E(2).5. Thus, the effects on smooth muscle of oxygen or glucose lack may also be mediated by reduction in the synthesis or effects of an intramural prostaglandin. Extension of this hypothesis to intestinal and vascular smooth muscle in vivo is discussed.

UI	MeSH Term	Description	Entries
D007213	Indomethacin	A non-steroidal anti-inflammatory agent (NSAID) that inhibits CYCLOOXYGENASE, which is necessary for the formation of PROSTAGLANDINS and other AUTACOIDS. It also inhibits the motility of POLYMORPHONUCLEAR LEUKOCYTES.	Amuno,Indocid,Indocin,Indomet 140,Indometacin,Indomethacin Hydrochloride,Metindol,Osmosin
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
D009129	Muscle Tonus	The state of activity or tension of a muscle beyond that related to its physical properties, that is, its active resistance to stretch. In skeletal muscle, tonus is dependent upon efferent innervation. (Stedman, 25th ed)	Muscle Tension,Muscle Tightness,Muscular Tension,Tension, Muscle,Tension, Muscular,Tightness, Muscle,Tonus, Muscle
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
D009584	Nitrogen	An element with the atomic symbol N, atomic number 7, and atomic weight [14.00643; 14.00728]. Nitrogen exists as a diatomic gas and makes up about 78% of the earth's atmosphere by volume. It is a constituent of proteins and nucleic acids and found in all living cells.
D010100	Oxygen	An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.	Dioxygen,Oxygen-16,Oxygen 16
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
D012007	Rectum	The distal segment of the LARGE INTESTINE, between the SIGMOID COLON and the ANAL CANAL.	Rectums
D002645	Chickens	Common name for the species Gallus gallus, the domestic fowl, in the family Phasianidae, order GALLIFORMES. It is descended from the red jungle fowl of SOUTHEAST ASIA.	Gallus gallus,Gallus domesticus,Gallus gallus domesticus,Chicken
D003106	Colon	The segment of LARGE INTESTINE between the CECUM and the RECTUM. It includes the ASCENDING COLON; the TRANSVERSE COLON; the DESCENDING COLON; and the SIGMOID COLON.	Appendix Epiploica,Taenia Coli,Omental Appendices,Omental Appendix,Appendices, Omental,Appendix, Omental