Biomaterial Database

Zinc ions block rectifier potassium channels and calcium activated potassium channels at the frog motor nerve endings. 1994

F Miralles, and C Canti, and J Marsal, and J Peres, and C Solsona

Servei de Neurologia, Facultat de Medicina, Hospital Princeps d'Espanya, Universitat de Barcelona, Spain.

The effect of Zn2+ on presynaptic currents was investigated on frog cutaneous pectoris nerve-muscle preparations. Nerve terminal spikes were recorded with extracellular electrodes placed in the perineurial sheaths of motor nerves. Zinc ions reversibly suppressed the component of the waveform associated with K+ currents--unmasking an inward current at the terminal--and induced repetitive firing when were applied to preparations perfused with calcium containing solutions. In experiments in which delayed rectifier channels were blocked by 3,4-diaminopyridine, Zn2+ caused a prolonged and reversible inward current associated with a slight decrease in the peak calcium current generated by 3,4-diaminopyridine. Zinc ions abolished the plateau calcium current produced by the simultaneous action of 3,4-diaminopyridine and tetraethylammonium. Finally, in all the preparations in which the exposure to Zn2+ was prolonged it was observed a dramatic and irreversible reduction of the presynaptic currents. These results suggest that Zn2+ has, at least, four different effects on presynaptic currents: (1) blockade of delayed rectifier potassium currents, (2) blockade of calcium-activated potassium currents, (3) blockade of calcium currents and (4) a delayed and irreversible disruption of all ionic conductances of the terminal.

UI	MeSH Term	Description	Entries
D009046	Motor Neurons	Neurons which activate MUSCLE CELLS.	Neurons, Motor,Alpha Motorneurons,Motoneurons,Motor Neurons, Alpha,Neurons, Alpha Motor,Alpha Motor Neuron,Alpha Motor Neurons,Alpha Motorneuron,Motoneuron,Motor Neuron,Motor Neuron, Alpha,Motorneuron, Alpha,Motorneurons, Alpha,Neuron, Alpha Motor,Neuron, Motor
D009132	Muscles	Contractile tissue that produces movement in animals.	Muscle Tissue,Muscle,Muscle Tissues,Tissue, Muscle,Tissues, Muscle
D009469	Neuromuscular Junction	The synapse between a neuron and a muscle.	Myoneural Junction,Nerve-Muscle Preparation,Junction, Myoneural,Junction, Neuromuscular,Junctions, Myoneural,Junctions, Neuromuscular,Myoneural Junctions,Nerve Muscle Preparation,Nerve-Muscle Preparations,Neuromuscular Junctions,Preparation, Nerve-Muscle,Preparations, Nerve-Muscle
D011894	Rana pipiens	A highly variable species of the family Ranidae in Canada, the United States and Central America. It is the most widely used Anuran in biomedical research.	Frog, Leopard,Leopard Frog,Lithobates pipiens,Frogs, Leopard,Leopard Frogs
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
D004492	Edetic Acid	A chelating agent that sequesters a variety of polyvalent cations such as CALCIUM. It is used in pharmaceutical manufacturing and as a food additive.	EDTA,Edathamil,Edetates,Ethylenediaminetetraacetic Acid,Tetracemate,Calcium Disodium Edetate,Calcium Disodium Versenate,Calcium Tetacine,Chelaton 3,Chromium EDTA,Copper EDTA,Coprin,Dicobalt EDTA,Disodium Calcitetracemate,Disodium EDTA,Disodium Ethylene Dinitrilotetraacetate,Distannous EDTA,Edetate Disodium Calcium,Edetic Acid, Calcium Salt,Edetic Acid, Calcium, Sodium Salt,Edetic Acid, Chromium Salt,Edetic Acid, Dipotassium Salt,Edetic Acid, Disodium Salt,Edetic Acid, Disodium Salt, Dihydrate,Edetic Acid, Disodium, Magnesium Salt,Edetic Acid, Disodium, Monopotassium Salt,Edetic Acid, Magnesium Salt,Edetic Acid, Monopotassium Salt,Edetic Acid, Monosodium Salt,Edetic Acid, Potassium Salt,Edetic Acid, Sodium Salt,Ethylene Dinitrilotetraacetate,Ethylenedinitrilotetraacetic Acid,Gallium EDTA,Magnesium Disodium EDTA,N,N'-1,2-Ethanediylbis(N-(carboxymethyl)glycine),Potassium EDTA,Stannous EDTA,Versenate,Versene,Acid, Edetic,Acid, Ethylenediaminetetraacetic,Acid, Ethylenedinitrilotetraacetic,Calcitetracemate, Disodium,Dinitrilotetraacetate, Disodium Ethylene,Dinitrilotetraacetate, Ethylene,Disodium Versenate, Calcium,EDTA, Chromium,EDTA, Copper,EDTA, Dicobalt,EDTA, Disodium,EDTA, Distannous,EDTA, Gallium,EDTA, Magnesium Disodium,EDTA, Potassium,EDTA, Stannous,Edetate, Calcium Disodium,Ethylene Dinitrilotetraacetate, Disodium,Tetacine, Calcium,Versenate, Calcium Disodium
D000077770	Amifampridine	4-Aminopyridine derivative that acts as a POTASSIUM CHANNEL blocker to increase release of ACETYLCHOLINE from nerve terminals. It is used in the treatment of CONGENITAL MYASTHENIC SYNDROMES.	Ruzurgi,3,4-Diaminopyridine,Amifampridine Phosphate,Firdapse,3,4 Diaminopyridine
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012867	Skin	The outer covering of the body that protects it from the environment. It is composed of the DERMIS and the EPIDERMIS.
D013757	Tetraethylammonium Compounds	Quaternary ammonium compounds that consist of an ammonium cation where the central nitrogen atom is bonded to four ethyl groups.	Tetramon,Tetrylammonium,Compounds, Tetraethylammonium