Biomaterial Database

The AC impedance of Necturus gallbladder epithelium. 1978

E Schifferdecker, and E Frömter

The impedance of Necturus gallbladder epithelium was determined using sine wave currents of 1 Hz to 30 kHz. In control Ringer's solution the impedance locus exhibited a simple semicircle with minute shift of the high frequency end along the real axis and a minute depression of the center below the real axis (average 0.9 +/- 0.7 degrees). Neglecting the slight suppression, the impedance of 1 cm2 of epithelium can be represented by an electrical analogue consisting of a parallel RC element of 115 +/- 26 omega and 5.16 +/- 0.9 muF in series with a small resistor of 5.3 +/- 1.3 omega. In agreement with experimental results obtained under ionic or osmotic substitutions, the applicability of this simple RC analogue to gallbladder epithelium under control conditions can be explained by the influence of the paracellular shunt and by assuming the time constants of the apical and basal cell membranes to be comparable. Based on these data and on voltage divider measurements obtained with microelectrodes the capacitances of the apical and basal cell membrane can be estimated to be approximately 7 and approximately 18 muF/cm2. The latter value agrees well with estimates of the surface folding obtained from electromicrographs, if the specific cell membrane capacitance is assumed to be approximately 1 muF/cm2 as in other cell membranes.

UI	MeSH Term	Description	Entries
D009994	Osmolar Concentration	The concentration of osmotically active particles in solution expressed in terms of osmoles of solute per liter of solution. Osmolality is expressed in terms of osmoles of solute per kilogram of solvent.	Ionic Strength,Osmolality,Osmolarity,Concentration, Osmolar,Concentrations, Osmolar,Ionic Strengths,Osmolalities,Osmolar Concentrations,Osmolarities,Strength, Ionic,Strengths, Ionic
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.
D004553	Electric Conductivity	The ability of a substrate to allow the passage of ELECTRONS.	Electrical Conductivity,Conductivity, Electric,Conductivity, Electrical
D004848	Epithelium	The layers of EPITHELIAL CELLS which cover the inner and outer surfaces of the cutaneous, mucus, and serous tissues and glands of the body.	Mesothelium,Epithelial Tissue,Mesothelial Tissue,Epithelial Tissues,Mesothelial Tissues,Tissue, Epithelial,Tissue, Mesothelial,Tissues, Epithelial,Tissues, Mesothelial
D005704	Gallbladder	A storage reservoir for BILE secretion. Gallbladder allows the delivery of bile acids at a high concentration and in a controlled manner, via the CYSTIC DUCT to the DUODENUM, for degradation of dietary lipid.	Gallbladders
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
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
D014562	Urodela	An order of the Amphibia class which includes salamanders and newts. They are characterized by usually having slim bodies and tails, four limbs of about equal size (except in Sirenidae), and a reduction in skull bones.	Amphiuma,Caudata,Eel, Congo,Salamanders,Congo Eel,Congo Eels,Eels, Congo,Salamander
D066298	In Vitro Techniques	Methods to study reactions or processes taking place in an artificial environment outside the living organism.	In Vitro Test,In Vitro Testing,In Vitro Tests,In Vitro as Topic,In Vitro,In Vitro Technique,In Vitro Testings,Technique, In Vitro,Techniques, In Vitro,Test, In Vitro,Testing, In Vitro,Testings, In Vitro,Tests, In Vitro,Vitro Testing, In