Biomaterial Database

Some effects of chemical irritants on the membrane of the giant amoeba. 1981

R W Foster, and A H Weston, and K M Weston

1 The effects of chemical irritants on the membrane potential and input resistance of the giant amoeba, Chaos carolinense, have been investigated. The membrane potential and input resistance were -111.5 mV and 8.6 M pi respectively. 2 In the resting state the cell membrane of Chaos carolinense was found to be impermeable to Na+ but permeable to K+. The distribution of K+ across the cell membrane conformed to a Donnan equilibrium with the resting membrane potential being the K+ equilibrium potential. 3 The chemical irritants dibenzoxazepine and its 2-chloro- and 3-chloro-analogues and o-chlorobenzylidene malononitrile produced a fall in input resistance but no change in membrane potential. It is suggested that these effects are caused by an increase in K+ permeability. 4 The potencies of a series of chemical irritants with respect to dibenzoxazepine were measured on the giant amoeba. These potencies did not reflect those found in mammalian preparations.

UI	MeSH Term	Description	Entries
D007509	Irritants	Drugs that act locally on cutaneous or mucosal surfaces to produce inflammation; those that cause redness due to hyperemia are rubefacients; those that raise blisters are vesicants and those that penetrate sebaceous glands and cause abscesses are pustulants; tear gases and mustard gases are also irritants.	Counterirritant,Counterirritants,Irritant,Pustulant,Pustulants,Rubefacient,Rubefacients,Vesicant,Vesicants
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
D009763	o-Chlorobenzylidenemalonitrile	A riot control agent which causes temporary irritation of the eyes and the mucosal surface of the respiratory tract. It is a more potent irritant than OMEGA-CHLOROACETOPHENONE, but less incapacitating.	o-Chlorobenzylidene Malonitrile,ortho-Chlorobenzylidenemalonitrile,2-Chlorobenzylidene Malonitrile,2-Chlorobenzylidenemalonitrile,CS Tear Gas,o-Chlorobenzylidene malonotrile,ortho-Chlorobenzylidene Malonitrile,2 Chlorobenzylidene Malonitrile,2 Chlorobenzylidenemalonitrile,Malonitrile, 2-Chlorobenzylidene,Malonitrile, o-Chlorobenzylidene,Malonitrile, ortho-Chlorobenzylidene,Tear Gas, CS,malonotrile, o-Chlorobenzylidene,o Chlorobenzylidene Malonitrile,o Chlorobenzylidene malonotrile,o Chlorobenzylidenemalonitrile,ortho Chlorobenzylidene Malonitrile,ortho Chlorobenzylidenemalonitrile
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.
D002211	Capsaicin	An alkylamide found in CAPSICUM that acts at TRPV CATION CHANNELS.	8-Methyl-N-Vanillyl-6-Nonenamide,Antiphlogistine Rub A-535 Capsaicin,Axsain,Capsaicine,Capsicum Farmaya,Capsidol,Capsin,Capzasin,Gelcen,Katrum,NGX-4010,Zacin,Zostrix,8 Methyl N Vanillyl 6 Nonenamide,NGX 4010,NGX4010
D003989	Dibenzoxazepines
D000656	Amoeba	A genus of ameboid protozoa. Characteristics include a vesicular nucleus and the formation of several PSEUDOPODIA, one of which is dominant at a given time. Reproduction occurs asexually by binary fission.	Ameba
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
D012965	Sodium Chloride	A ubiquitous sodium salt that is commonly used to season food.	Sodium Chloride, (22)Na,Sodium Chloride, (24)NaCl