Biomaterial Database

Influence of extracellular magnesium on the contractile and endothelium-dependent dilatory responses of feline mesenteric arteries. 1991

C Szabó, and M Faragó, and E Dóra, and I Horváth, and A G Kovách

Experimental Research Department, Semmelweis University Medical School, Budapest, Hungary.

To clarify the effect of extracellular magnesium on the vascular reactivity of feline isolated mesenteric arteries, the effects of slight alterations in the extracellular magnesium concentration on the contractile and endothelium-dependent dilatory responses were investigated in vitro. The contractions, induced by noradrenaline 10(-8)-10(-5) M, were not affected in the mesenteric artery at low extracellular magnesium (0.8 mM versus to the normal, 1.2 mM). High (1.6 and 2.0 mM) magnesium exerted a modest inhibitory effect on the contractile responses. This depression of the contraction was accompanied with a significant shift to the right in the EC50 value for noradrenaline. The endothelium-dependent relaxations induced by acetylcholine 10(-8)-10(-5) M, were inhibited by high (1.6 and 2.0 mM) magnesium. Lowering of the extracellular magnesium concentration to 0.8 mM, however, failed to alter the dilatory potency of acetylcholine. The depression of the dilatory responses was also accompanied with a shift to the right in the EC50 values for acetylcholine. The present results show, that contractions and endothelium-dependent relaxations of the mesenteric artery are modulated by the extracellular magnesium asymmetrically: slight magnesium deficiency does not affect these responses, whereas elevation of the concentration of this ion inhibits both processes. Extracellular magnesium probably affects rather the binding of these contractile and endothelium-dependent dilatory agonists to their receptors than the calcium influx into the endothelial- and smooth muscle cells in this vessel.

UI	MeSH Term	Description	Entries
D008274	Magnesium	A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.
D008297	Male		Males
D008638	Mesenteric Arteries	Arteries which arise from the abdominal aorta and distribute to most of the intestines.	Arteries, Mesenteric,Artery, Mesenteric,Mesenteric Artery
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
D009131	Muscle, Smooth, Vascular	The nonstriated involuntary muscle tissue of blood vessels.	Vascular Smooth Muscle,Muscle, Vascular Smooth,Muscles, Vascular Smooth,Smooth Muscle, Vascular,Smooth Muscles, Vascular,Vascular Smooth Muscles
D009638	Norepinephrine	Precursor of epinephrine that is secreted by the ADRENAL MEDULLA and is a widespread central and autonomic neurotransmitter. Norepinephrine is the principal transmitter of most postganglionic sympathetic fibers, and of the diffuse projection system in the brain that arises from the LOCUS CERULEUS. It is also found in plants and is used pharmacologically as a sympathomimetic.	Levarterenol,Levonorepinephrine,Noradrenaline,Arterenol,Levonor,Levophed,Levophed Bitartrate,Noradrenaline Bitartrate,Noradrénaline tartrate renaudin,Norepinephrin d-Tartrate (1:1),Norepinephrine Bitartrate,Norepinephrine Hydrochloride,Norepinephrine Hydrochloride, (+)-Isomer,Norepinephrine Hydrochloride, (+,-)-Isomer,Norepinephrine d-Tartrate (1:1),Norepinephrine l-Tartrate (1:1),Norepinephrine l-Tartrate (1:1), (+,-)-Isomer,Norepinephrine l-Tartrate (1:1), Monohydrate,Norepinephrine l-Tartrate (1:1), Monohydrate, (+)-Isomer,Norepinephrine l-Tartrate (1:2),Norepinephrine l-Tartrate, (+)-Isomer,Norepinephrine, (+)-Isomer,Norepinephrine, (+,-)-Isomer
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D002415	Cats	The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)	Felis catus,Felis domesticus,Domestic Cats,Felis domestica,Felis sylvestris catus,Cat,Cat, Domestic,Cats, Domestic,Domestic Cat
D004730	Endothelium, Vascular	Single pavement layer of cells which line the luminal surface of the entire vascular system and regulate the transport of macromolecules and blood components.	Capillary Endothelium,Vascular Endothelium,Capillary Endotheliums,Endothelium, Capillary,Endotheliums, Capillary,Endotheliums, Vascular,Vascular Endotheliums
D005260	Female		Females