Biomaterial Database

Electroneutral transport of organic cations in canine renal brush border membrane vesicles (BBMV). 1985

P P Sokol, and P D Holohan, and C R Ross

The effect of potential difference on the organic cation/H+ antiport system located in brush border membrane vesicles was examined. Potential difference was generated using K+ gradients and a K+-specific ionophore, valinomycin. Transport of a prototypic organic cation, 1N-[3H]methylnicotinamide (NMN), was assessed under conditions where K+ diffusion potentials generated transient intravesicular negative and positive states. The results demonstrate that NMN transport is independent of potential difference. The organic cation/H+ coupling ratio was studied by imposing transmembrane H+ and NMN gradients of varying magnitudes and measuring net flux of NMN for a 5-sec period. Consistent with an equilibrium thermodynamics model, no net NMN flux is observed when the NMN gradient from out to in is equal to the H+ gradient from out to in ([NMN]o/[NMN]i equals [H+]o/[H+]i). This suggests that the carrier is at equilibrium and that the stoichiometry for the organic cation/H+ antiport is 1:1.

UI	MeSH Term	Description	Entries
D007668	Kidney	Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.	Kidneys
D008871	Microvilli	Minute projections of cell membranes which greatly increase the surface area of the cell.	Brush Border,Striated Border,Border, Brush,Border, Striated,Borders, Brush,Borders, Striated,Brush Borders,Microvillus,Striated Borders
D009536	Niacinamide	An important compound functioning as a component of the coenzyme NAD. Its primary significance is in the prevention and/or cure of blacktongue and PELLAGRA. Most animals cannot manufacture this compound in amounts sufficient to prevent nutritional deficiency and it therefore must be supplemented through dietary intake.	Nicotinamide,Vitamin B 3,Vitamin PP,3-Pyridinecarboxamide,Enduramide,Nicobion,Nicotinsäureamid Jenapharm,Papulex,Vitamin B3,3 Pyridinecarboxamide,B 3, Vitamin,B3, Vitamin,Jenapharm, Nicotinsäureamid
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.
D002412	Cations	Positively charged atoms, radicals or groups of atoms which travel to the cathode or negative pole during electrolysis.	Cation
D004058	Diffusion	The tendency of a gas or solute to pass from a point of higher pressure or concentration to a point of lower pressure or concentration and to distribute itself throughout the available space. Diffusion, especially FACILITATED DIFFUSION, is a major mechanism of BIOLOGICAL TRANSPORT.	Diffusions
D004285	Dogs	The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)	Canis familiaris,Dog
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
D001692	Biological Transport	The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.	Transport, Biological,Biologic Transport,Transport, Biologic
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