Biomaterial Database

Evidence for independent Cl- and HCO3- secretion and involvement of an apical Na(+)-HCO3- cotransporter in cultured rat epididymal epithelia. 1996

H C Chan, and W H Ko, and W Zhao, and W O Fu, and P Y Wong

Department of Physiology, Chinese University of Hong Kong, Shatin, New Territories, Hong Kong.

Electrogenic chloride and bicarbonate secretion by cultured rat epididymal epithelia was studied using the short-circuit current (ISC) technique. When incubated in normal solution, 8-(4-chlorophenylthio)-adenosine 3',5'-cyclic monophosphate (cpt-cAMP) caused a rise in the ISC, which was attributable to Cl- and HCO3- secretion. Cl- secretion was found to contribute to the initial transient phase, whereas HCO3- secretion contributed to the sustained phase of the response. HCO3- secretion involves a basolaterally placed Na(+)-H+ exchanger and apical anion channel, most probably the cystic fibrosis transmembrane conductance regulator (CFTR). There is also evidence that an apical electrogenic Na(+)-HCO3- cotransporter is involved in HCO3- exit. CFTR accounted for 70% of HCO3- secretion, while the Na(+)-HCO3- cotransporter accounted for 30%. The possibility that the cotransporter may serve as an alternative pathway for HCO3- secretion in cystic fibrosis is discussed.

UI	MeSH Term	Description	Entries
D008297	Male		Males
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
D002034	Bumetanide	A sulfamyl diuretic.	Bumedyl,Bumethanide,Bumex,Burinex,Drenural,Fordiuran,Miccil,PF-1593,PF 1593,PF1593
D002352	Carrier Proteins	Proteins that bind or transport specific substances in the blood, within the cell, or across cell membranes.	Binding Proteins,Carrier Protein,Transport Protein,Transport Proteins,Binding Protein,Protein, Carrier,Proteins, Carrier
D002478	Cells, Cultured	Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.	Cultured Cells,Cell, Cultured,Cultured Cell
D002712	Chlorides	Inorganic compounds derived from hydrochloric acid that contain the Cl- ion.	Chloride,Chloride Ion Level,Ion Level, Chloride,Level, Chloride Ion
D003470	Culture Media	Any liquid or solid preparation made specifically for the growth, storage, or transport of microorganisms or other types of cells. The variety of media that exist allow for the culturing of specific microorganisms and cell types, such as differential media, selective media, test media, and defined media. Solid media consist of liquid media that have been solidified with an agent such as AGAR or GELATIN.	Media, Culture
D004594	Electrophysiology	The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.
D004822	Epididymis	The convoluted cordlike structure attached to the posterior of the TESTIS. Epididymis consists of the head (caput), the body (corpus), and the tail (cauda). A network of ducts leaving the testis joins into a common epididymal tubule proper which provides the transport, storage, and maturation of SPERMATOZOA.
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