Biomaterial Database

Recovery of membrane potentials from diamide-induced depolarization in frog lens fibers. 1983

T Taura, and R Teshima, and T Murata

Measurement of membrane potentials in isolated frog lens fibers was made by means of intracellular microelectrode techniques. The membrane potentials of lens fibers were depolarized to various degrees after exposure to diamide, an -SH inhibitor. When the degree of diamide-induced depolarization was less than 20 mV, the membrane potentials almost fully recovered to the control level within 12 h after immersion in a Ringer's solution containing dithiothreitol (DTT), a -SH protector. A similar tendency was also recognized in some lenses (57%) whose depolarization was 30 mV. When the degree of depolarization was 40 mV, the membrane potentials further depolarized in all cases tested in spite of treatment with DTT. From this study, it is considered that frog lens fibers could not recover their function if the damage was so severe as to produce a membrane depolarization of more 40 mV. Determination of ionic concentrations in lens fibers revealed a highly significant correlation between the degree of diamide-induced depolarization and changes in concentration ratio of Na+/K+.

UI	MeSH Term	Description	Entries
D007908	Lens, Crystalline	A transparent, biconvex structure of the EYE, enclosed in a capsule and situated behind the IRIS and in front of the vitreous humor (VITREOUS BODY). It is slightly overlapped at its margin by the ciliary processes. Adaptation by the CILIARY BODY is crucial for OCULAR ACCOMMODATION.	Eye Lens,Lens, Eye,Crystalline Lens
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
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.
D011892	Rana catesbeiana	A species of the family Ranidae (true frogs). The only anuran properly referred to by the common name "bullfrog", it is the largest native anuran in North America.	Bullfrog,Bullfrogs,Rana catesbeianas,catesbeiana, Rana
D003958	Diamide	A sulfhydryl reagent which oxidizes sulfhydryl groups to the disulfide form. It is a radiation-sensitizing agent of anoxic bacterial and mammalian cells.	Diazodicarboxylic Acid Bis(N,N-dimethyl)amide,Diazodicarboxylic Acid Bisdimethylamide,Dizene Dicarboxylic Acid Bis(N,N-dimethylamide),Dizenedicarboxylic Acid Bis(N,N-dimethylamide),Tetramethylazoformamide,Acid Bisdimethylamide, Diazodicarboxylic,Bisdimethylamide, Diazodicarboxylic Acid
D004229	Dithiothreitol	A reagent commonly used in biochemical studies as a protective agent to prevent the oxidation of SH (thiol) groups and for reducing disulphides to dithiols.	Cleland Reagent,Cleland's Reagent,Sputolysin,Clelands Reagent,Reagent, Cleland,Reagent, Cleland's
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
D001391	Azo Compounds	Organic chemicals where aryl or alkyl groups are joined by two nitrogen atoms through a double bond (R-N	Azo Dye,Azo Dyes,Compounds, Azo,Dye, Azo,Dyes, Azo
D012964	Sodium	A member of the alkali group of metals. It has the atomic symbol Na, atomic number 11, and atomic weight 23.	Sodium Ion Level,Sodium-23,Ion Level, Sodium,Level, Sodium Ion,Sodium 23