-transparent.png){kind=logo}
Binding and transport characteristics for uptake of taurocholic acid by isolated rat liver cells were studied. 1. An adsorption of taurocholate to the cell surface is terminated in less than 15 s. A Ks of 0.55 mM and a total binding capacity of 3.8 nmol/mg cell protein is determined. 2. The rate of uptake of taurocholate follows Michaelis-Menten kinetics with Km = 19 muM and V = 1.7 nmol/mg protein min. 3. There is a broad pH optimum for uptake between pH 6.5 -- 8.0. 4. The activation energy amounts to 29 kcal/mol. At high taurocholate concentration an unusual upward bend is observed in the Arrhenius plot. 5. Taurocholate uptake is competitively inhibited by taurochenodeoxycholate (Ki = 9 muM). It is noncompetitively inhibited by bromosulfophthalein (Ki = 3 muM). 6. At physiological taurocholate concentrations a 200-fold intracellular accumulation of taurocholate is observed. 7. Uptake is inhibited by about 75% by either antimycin A, carbonylcyanide m-chlorophenyl-hydrazone, ouabain. 8. Replacement of extracellular Na+ by either K+ or sucrose results in a 75% decrease of uptake. 9. It is concluded that taurocholate uptake is a carrier-mediated process, and suggested that the energy for intracellular accumulation is made available by cotransport of Na+.
L R Schwarz, and
R Burr, and
M Schwenk, and
E Pfaff, and
H Greim
August 1986,
Biochimica et biophysica acta,
L R Schwarz, and
R Burr, and
M Schwenk, and
E Pfaff, and
H Greim
December 1986,
Biochimica et biophysica acta,
L R Schwarz, and
R Burr, and
M Schwenk, and
E Pfaff, and
H Greim
October 1969,
The Biochemical journal,
L R Schwarz, and
R Burr, and
M Schwenk, and
E Pfaff, and
H Greim
July 1978,
Naunyn-Schmiedeberg's archives of pharmacology,
L R Schwarz, and
R Burr, and
M Schwenk, and
E Pfaff, and
H Greim
September 1994,
The American journal of physiology,
L R Schwarz, and
R Burr, and
M Schwenk, and
E Pfaff, and
H Greim
August 1990,
Archives of biochemistry and biophysics,
L R Schwarz, and
R Burr, and
M Schwenk, and
E Pfaff, and
H Greim
February 1997,
Clinica chimica acta; international journal of clinical chemistry,
L R Schwarz, and
R Burr, and
M Schwenk, and
E Pfaff, and
H Greim
August 1981,
Biochimica et biophysica acta,
L R Schwarz, and
R Burr, and
M Schwenk, and
E Pfaff, and
H Greim
June 1983,
The Journal of nutrition,
L R Schwarz, and
R Burr, and
M Schwenk, and
E Pfaff, and
H Greim
June 1991,
The Journal of steroid biochemistry and molecular biology,
