Biomaterial Database

Protective effects of manganese, cobalt, nickel, and barium against a calcium paradox in the isolated frog heart. 1991

M Touraki, and I Beis

Laboratory of Animal Physiology, School of Sciences, University of Thessaloniki, Greece.

The effect of inorganic slow channel blockers on the calcium paradox in the frog heart was examined. Addition of the divalent cations of manganese, cobalt, nickel, or barium during calcium depletion protected the frog heart against a calcium paradox. This protective effect was indicated by reduced protein release, maintenance of electrical activity, and recovery of mechanical activity during reperfusion. Tissue calcium determination results showed that in the control paradox in the absence of divalent cations, there is an efflux of calcium from myocardial cells during calcium depletion and a massive influx of calcium during the following reperfusion, leading to a calcium overload. Divalent cations protected frog myocardial cells, when present in the calcium-free perfusion medium, by reducing both calcium efflux during calcium depletion and the massive calcium influx during reperfusion. The effectiveness of the added divalent cations showed a strong dependence upon their ionic radius. The most potent inhibitors of the calcium paradox in the frog heart were the divalent cations having an ionic radius closer to the ionic radius of calcium. These results are discussed in terms of the possible mechanism involved in the protective effect of manganese, cobalt, nickel, and barium.

UI	MeSH Term	Description	Entries
D008345	Manganese	A trace element with atomic symbol Mn, atomic number 25, and atomic weight 54.94. It is concentrated in cell mitochondria, mostly in the pituitary gland, liver, pancreas, kidney, and bone, influences the synthesis of mucopolysaccharides, stimulates hepatic synthesis of cholesterol and fatty acids, and is a cofactor in many enzymes, including arginase and alkaline phosphatase in the liver. (From AMA Drug Evaluations Annual 1992, p2035)
D009200	Myocardial Contraction	Contractile activity of the MYOCARDIUM.	Heart Contractility,Inotropism, Cardiac,Cardiac Inotropism,Cardiac Inotropisms,Contractilities, Heart,Contractility, Heart,Contraction, Myocardial,Contractions, Myocardial,Heart Contractilities,Inotropisms, Cardiac,Myocardial Contractions
D009206	Myocardium	The muscle tissue of the HEART. It is composed of striated, involuntary muscle cells (MYOCYTES, CARDIAC) connected to form the contractile pump to generate blood flow.	Muscle, Cardiac,Muscle, Heart,Cardiac Muscle,Myocardia,Cardiac Muscles,Heart Muscle,Heart Muscles,Muscles, Cardiac,Muscles, Heart
D009532	Nickel	A trace element with the atomic symbol Ni, atomic number 28, and atomic weight 58.69. It is a cofactor of the enzyme UREASE.
D010477	Perfusion	Treatment process involving the injection of fluid into an organ or tissue.	Perfusions
D011895	Rana ridibunda	A species of the family Ranidae which occurs primarily in Europe and is used widely in biomedical research.
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
D002121	Calcium Channel Blockers	A class of drugs that act by selective inhibition of calcium influx through cellular membranes.	Calcium Antagonists, Exogenous,Calcium Blockaders, Exogenous,Calcium Channel Antagonist,Calcium Channel Blocker,Calcium Channel Blocking Drug,Calcium Inhibitors, Exogenous,Channel Blockers, Calcium,Exogenous Calcium Blockader,Exogenous Calcium Inhibitor,Calcium Channel Antagonists,Calcium Channel Blocking Drugs,Exogenous Calcium Antagonists,Exogenous Calcium Blockaders,Exogenous Calcium Inhibitors,Antagonist, Calcium Channel,Antagonists, Calcium Channel,Antagonists, Exogenous Calcium,Blockader, Exogenous Calcium,Blocker, Calcium Channel,Blockers, Calcium Channel,Calcium Blockader, Exogenous,Calcium Inhibitor, Exogenous,Channel Antagonist, Calcium,Channel Blocker, Calcium,Inhibitor, Exogenous Calcium
D002413	Cations, Divalent	Positively charged atoms, radicals or groups of atoms with a valence of plus 2, which travel to the cathode or negative pole during electrolysis.	Divalent Cations
D003035	Cobalt	A trace element that is a component of vitamin B12. It has the atomic symbol Co, atomic number 27, and atomic weight 58.93. It is used in nuclear weapons, alloys, and pigments. Deficiency in animals leads to anemia; its excess in humans can lead to erythrocytosis.	Cobalt-59,Cobalt 59