✦ LIBER ✦

Phosphate transport in Ehrlich ascites tumor cells: Inhibition by H+

✍ Scribed by Jesse W. Bowen; Charles Levinson

Publisher: John Wiley and Sons
Year: 1986
Tongue: English
Weight: 608 KB
Volume: 128
Category: Article
ISSN: 0021-9541
DOI: 10.1002/jcp.1041280110

No coin nor oath required. For personal study only.

✦ Synopsis

The effect of changes in extracellular pH (pH,) and intracellular pH (pHJ on Na+-dependent and Na+-independent inorganic phosphate (Pi) transport in Ehrlich cells was investigated. In the presence of Na+, acutely reducing pH, from 7.30 to 5.50 results first in a transient (-7 min) stimulation of Pi transport. The enhanced rate of transport is a saturable function of the extracellular [H+]; the Ks equals 2.3 x M (pH, 6.68). However, Pi transport is progressively inhibited as pHi falls below 6.50. The effect of pHi on Pi transport measured at various intracellular "a+] suggests that inhibition develops as a consequence of H + interaction with an intracellular Na+ site($ on the Na+dependent carrier. At pH, 7.4, about 15% of the steady state Pi flux persists in the absence of Na+. However, when pH, is reduced, transport is stimulated to the same extent and with the same time course and kinetic characteristics as in the presence of Na+. Thus, H + stimulated Pi transport does not require Na+, raising the possibility that the Na+-independent component is mediated by the anion (CI-) exchanger.

📜 SIMILAR VOLUMES

Evidence for monovalent phosphate transp

Evidence for monovalent phosphate transport in Ehrlich ascites tumor cells

✍ Jesse W. Bowen; Charles Levinson 📂 Article 📅 1983 🏛 John Wiley and Sons 🌐 English ⚖ 744 KB

In an effort to determine whether the Na+-dependent P, transport system of Ehrlich ascites tumor cells exhibits specificity for H,PO, or HPO, :, P, fluxes were determined by measuring "P,-P, self-exchange. Three experimental approaches were employed. First, the effect of pH on steady-state P, transp

Self-inhibition of chloride transport in

Self-inhibition of chloride transport in ehrlich ascites tumor cells

✍ Charles Levinson 📂 Article 📅 1984 🏛 John Wiley and Sons 🌐 English ⚖ 803 KB

## Abstract Previous studies have shown that mediated Cl^−^ transport which occurs by at least two processes (Cl^−^‐dependent cation cotransport and Cl^−^ self‐exchange) becomes progressively inhibited when extracellular Cl^−^ exceeds about 60 mM (Hoffmann et al., 1979). To account for this type of

Phosphate transport in ehrlich ascites t

Phosphate transport in ehrlich ascites tumor cells and the effect of arsenate

✍ Charles Levinson 📂 Article 📅 1972 🏛 John Wiley and Sons 🌐 English ⚖ 401 KB 👁 1 views

The effect of extracellular Pi and arsenate on Pi-transport in Ehrlich ascites tumor cells has been studied. Pi-transport can be described by Michaelis-Menten kinetics; the maximal flux equal to 44 mmoles (kg cell water)-' hour-' and K m equal to 3.3 X 1 0 -4 M. Arsenate is a competitive inhibitor o

Phosphate concentration and transport in

Phosphate concentration and transport in Ehrlich ascites tumor cells: Effect of sodium

✍ Jesse W. Bowen; Charles Levinson 📂 Article 📅 1982 🏛 John Wiley and Sons 🌐 English ⚖ 619 KB

The effects of extracellular P, and Na' on cellular Pi concentration and transport were studied. Steady-state P, exchange flux was measured by 3zP uptake in the presence and absence of Na'. Model experiments were also conducted to assess t h e possibility that hydrolysis of organic phosphate esters

The transport of chloride in ehrlich asc

The transport of chloride in ehrlich ascites tumor cells

✍ Charles Levinson; Mitchel L. Villereal 📂 Article 📅 1976 🏛 John Wiley and Sons 🌐 English ⚖ 785 KB

## Abstract The steady state transport and distribution of chloride between the intracellular and extracellular phases was investigated when the extracellular chloride concentration was varied by isosmotic replacement with nitrate, bromide and acetate. The results of these experiments show that chl

Calcium transport and distribution in eh

Calcium transport and distribution in ehrlich mouse ascites tumor cells

✍ Dr. Charles Levinson; Leslie E. Blumenson 📂 Article 📅 1970 🏛 John Wiley and Sons 🌐 English ⚖ 693 KB

## Abstract Data from isotopic uptake experiments were used to measure calcium fluxes and compartment sizes in ascites tumor cells. The data were analyzed with two kinetic models, A and B. In 80% of the experiments model A, which is based on one exchangeable calcium compartment, was rejected in fav