Biomaterial Database

Mechanism of action of triethyltin on identified leech neurons. 1990

M A Kyriakides, and R T Sawyer, and S L Allen, and M G Simpson

Neuropharm Ltd., Hendy, Dyfed, U.K.

The effects of triethyltin (TET) have been examined using intracellular electrophysiological recording techniques from identified neurons of the leech (Hirudo medicinalis) CNS and from salivary glands of the giant Amazon leech (Haementeria ghilianii). TET, at concentrations as low as 10(-5) M, caused a reversible neuronal membrane depolarisation accompanied by an increase in firing frequency of action potentials (which could lead to conduction block at 10(-4) M) and a concomitant decrease in membrane resistance. TET-induced membrane depolarisation still occurred in saline where Na+, K+ and Ca2+ had been replaced by choline. TET decreased the rate of the depolarising and repolarising phases of the action potential. This also occurred in Haementeria salivary gland cells, in which the only inward cation channel is a calcium channel. The calcium channel blocker, manganese, did not block the effects of TET. TET counteracted the effects on the action potential of the potassium channel blocker, tetraethylammonium chloride (TEA). TET-induced neurotoxicity occurred independently of any resultant toxic effects on the myelin sheath. The action of TET is consistent with our view that it causes an increase of intracellular free Ca2+ probably via release from intracellular stores and inhibition of Ca2+ reuptake. A resulting inhibition of the Na+/K+ and Ca2+ pumps may also occur.

UI	MeSH Term	Description	Entries
D007473	Ion Channels	Gated, ion-selective glycoproteins that traverse membranes. The stimulus for ION CHANNEL GATING can be due to a variety of stimuli such as LIGANDS, a TRANSMEMBRANE POTENTIAL DIFFERENCE, mechanical deformation or through INTRACELLULAR SIGNALING PEPTIDES AND PROTEINS.	Membrane Channels,Ion Channel,Ionic Channel,Ionic Channels,Membrane Channel,Channel, Ion,Channel, Ionic,Channel, Membrane,Channels, Ion,Channels, Ionic,Channels, Membrane
D007865	Leeches	Annelids of the class Hirudinea. Some species, the bloodsuckers, may become temporarily parasitic upon animals, including man. Medicinal leeches (HIRUDO MEDICINALIS) have been used therapeutically for drawing blood since ancient times.	Hirudinea,Hirudineas,Leeche
D008564	Membrane Potentials	The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).	Resting Potentials,Transmembrane Potentials,Delta Psi,Resting Membrane Potential,Transmembrane Electrical Potential Difference,Transmembrane Potential Difference,Difference, Transmembrane Potential,Differences, Transmembrane Potential,Membrane Potential,Membrane Potential, Resting,Membrane Potentials, Resting,Potential Difference, Transmembrane,Potential Differences, Transmembrane,Potential, Membrane,Potential, Resting,Potential, Transmembrane,Potentials, Membrane,Potentials, Resting,Potentials, Transmembrane,Resting Membrane Potentials,Resting Potential,Transmembrane Potential,Transmembrane Potential Differences
D009474	Neurons	The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.	Nerve Cells,Cell, Nerve,Cells, Nerve,Nerve Cell,Neuron
D011188	Potassium	An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.
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
D000200	Action Potentials	Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.	Spike Potentials,Nerve Impulses,Action Potential,Impulse, Nerve,Impulses, Nerve,Nerve Impulse,Potential, Action,Potential, Spike,Potentials, Action,Potentials, Spike,Spike Potential
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
D012469	Salivary Glands	Glands that secrete SALIVA in the MOUTH. There are three pairs of salivary glands (PAROTID GLAND; SUBLINGUAL GLAND; SUBMANDIBULAR GLAND).	Gland, Salivary,Glands, Salivary,Salivary Gland
D014267	Triethyltin Compounds	Organic compounds composed of tin and three ethyl groups. Affect mitochondrial metabolism and inhibit oxidative phosphorylation by acting directly on the energy conserving processes.	Compounds, Triethyltin