Biomaterial Database

Effects of divalent cations on chloride movement across amphibian skin. 1988

W Nagel, and Y Natochin, and J Crabbé

Physiologisches Institut der Universität München, Federal Republic of Germany.

Effects of the divalent heavy metal ions Cd2+, Co2+, Cu2+, Mn2+, Ni2+, and Zn2+ on pathways for sodium and chloride were assessed on isolated amphibian skin (Rana temporaria and esculenta, Bufo marinus and viridis). It was observed that these agents, in addition to the previously reported stimulation of sodium transport, inhibit chloride-related tissue conductance (gCl) in frog skin with spontaneously high gCl when added to the external incubation medium. Serosal application was ineffective. Half-maximal inhibition of gt occurred at approximately 0.2 mmol/l Ni2+ and Zn2+, 0.5 mmol/l Co2+ and Cd2+, and more than 3 mmol/l Mn2+. The onset of inhibition was rapid, steady state values being reached within 3 min; reversibility was complete with approximately similar time course. Cu2+, which could not be tested at concentrations above 0.1 mmol/l, had only minimal and poorly reversible effect on gCl. Skin of Bufo was virtually insensitive to these metal ions. Microelectrode determinations demonstrate that the decrease of conductance was restricted to a pathway distinct from the principal cells which show, on the contrary, increase of apical membrane conductance originating from stimulation of sodium permeability. The metal ions might be valuable for characterization of the pathway and the mechanism of transepithelial conductive chloride transport.

UI	MeSH Term	Description	Entries
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
D008670	Metals	Electropositive chemical elements characterized by ductility, malleability, luster, and conductance of heat and electricity. They can replace the hydrogen of an acid and form bases with hydroxyl radicals. (Grant & Hackh's Chemical Dictionary, 5th ed)	Metal
D011893	Rana esculenta	An edible species of the family Ranidae, occurring in Europe and used extensively in biomedical research. Commonly referred to as "edible frog".	Pelophylax esculentus
D011896	Rana temporaria	A species of the family Ranidae occurring in a wide variety of habitats from within the Arctic Circle to South Africa, Australia, etc.	European Common Frog,Frog, Common European,Common European Frog,Common Frog, European,European Frog, Common,Frog, European Common
D002024	Bufo marinus	A species of the true toads, Bufonidae, becoming fairly common in the southern United States and almost pantropical. The secretions from the skin glands of this species are very toxic to animals.	Rhinella marina,Toad, Giant,Toad, Marine,Giant Toad,Giant Toads,Marine Toad,Marine Toads,Toads, Giant,Toads, Marine
D002025	Bufonidae	The family of true toads belonging to the order Anura. The genera include Bufo, Ansonia, Nectophrynoides, and Atelopus.	Bufo,Toads, True,Bufos,Toad, True,True Toad,True Toads
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
D002712	Chlorides	Inorganic compounds derived from hydrochloric acid that contain the Cl- ion.	Chloride,Chloride Ion Level,Ion Level, Chloride,Level, Chloride Ion
D005712	Galvanic Skin Response	A change in electrical resistance of the skin, occurring in emotion and in certain other conditions.	Electric Conductance, Skin,Electrodermal Response,Reflex, Psychogalvanic,Skin Electric Conductance,Conductance, Skin Electric,Conductances, Skin Electric,Electric Conductances, Skin,Electrodermal Responses,Galvanic Skin Responses,Psychogalvanic Reflex,Response, Electrodermal,Response, Galvanic Skin,Responses, Electrodermal,Responses, Galvanic Skin,Skin Response, Galvanic,Skin Responses, Galvanic
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