Numerical analysis reveals complexities of glutamate transport.
The uptake of radiolabeled glutamate into cultured human (HeLa S3) and hamster (CHO-K1) cells was analyzed according to modified Michaelis-Menten models fit by the Marquardt least-squares method. Kinetic parameters not previously reported for these cells were obtained. Some rarely used features available with this fitting method proved to be extremely helpful. Most importantly, a goodness-of-fit measure revealed a significant alteration of glutamate uptake in HeLa cells that was induced by starvation. This apparent regulation, unexpected for glutamate transport, might have been missed if the fit had been judged by eye or by the magnitude of parameter standard deviations. Techniques for analyzing parameter distributions, improving experimental design and performing tests of significance are also described.
Ash
J F
JF
Department of Anatomy, School of Medicine, University of Utah, Salt Lake City 84132.
Igo
R P
RP
D000818:Animals; D016466:CHO Cells / Q000378:metabolism; D003198:Computer Simulation; D006224:Cricetinae; D005971:Glutamates / Q000378:metabolism*; D018698:Glutamic Acid; D006367:HeLa Cells / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D009010:Monte Carlo Method
D005971:Glutamates; D018698:Glutamic Acid