Kinetics of growth and glucose transport in glucose-limited chemostat cultures ofSaccharomyces cerevisiae CBS 8066

Yeast ◽  
1989 ◽  
Vol 5 (3) ◽  
pp. 159-165 ◽  
Author(s):  
Erik Postma ◽  
W. Alexander Scheffers ◽  
Johannes P. Van Dijken
Keyword(s):  
Glucose Transport ◽  
Chemostat Cultures ◽  
Kinetics Of

Kinetics of unidirectional glucose transport into the isolated dog brain

1973 ◽  
Vol 225 (3) ◽  
pp. 586-592 ◽  
Author(s):  
AL Betz ◽  
DD Gilboe ◽  
DL Yudilevich ◽  
LR Drewes
Keyword(s):  
Glucose Transport ◽  
Dog Brain ◽  
Kinetics Of

scholarly journals Hexokinase Regulates Kinetics of Glucose Transport and Expression of Genes Encoding Hexose Transporters inSaccharomyces cerevisiae

2000 ◽  
Vol 182 (23) ◽  
pp. 6815-6818 ◽  
Author(s):  
Thomas Petit ◽  
Jasper A. Diderich ◽  
Arthur L. Kruckeberg ◽  
Carlos Gancedo ◽  
Karel Van Dam
Keyword(s):  
Glucose Transport ◽  
Mrna Levels ◽  
High Affinity ◽  
Expression Of Genes ◽  
Hexose Transporters ◽  
Genes Encoding ◽  
High Concentrations ◽  
Kinetics Of ◽  
Very High ◽  
Null Strain

ABSTRACT Glucose transport kinetics and mRNA levels of different glucose transporters were determined in Saccharomyces cerevisiaestrains expressing different sugar kinases. During exponential growth on glucose, a hxk2 null strain exhibited high-affinity hexose transport associated with an elevated transcription of the genesHXT2 and HXT7, encoding high-affinity transporters, and a diminished expression of the HXT1 andHXT3 genes, encoding low-affinity transporters. Deletion ofHXT7 revealed that the high-affinity component is mostly due to HXT7; however, a previously unidentified very-high-affinity component (Km = 0.19 mM) appeared to be due to other factors. Expression of genes encoding hexokinases from Schizosaccharomyces pombe orYarrowia lipolytica in a hxk1 hxk2 glk1 strain prevented derepression of the high-affinity transport system at high concentrations of glucose.

Kinetics of glucose transport and sequestration in lactating bovine mammary glands measured in vivo with a paired indicator/nutrient dilution technique

2005 ◽  
Vol 99 (3) ◽  
pp. 799-806 ◽  
Author(s):  
Fulong Qiao ◽  
Donald R. Trout ◽  
Changting Xiao ◽  
John P. Cant
Keyword(s):  
Glucose Transport ◽  
Goodness Of Fit ◽  
Mammary Glands ◽  
Integration Model ◽  
Intracellular Space ◽  
First Order ◽  
Extracellular Glucose ◽  
Kinetics Of ◽  
Dilution Curves

To quantify kinetics of mammary glucose utilization in vivo, 24 paired glucose and extracellular indicator ( p-aminohippuric acid) dilution curves across intact bovine mammary glands were obtained after bolus injections into the external iliac artery. Dilution curves were analyzed using a compartmental capillary, convolution integration model. Four candidate submodels of glucose transport and metabolism in capillary supply zones were fit to the glucose dilution curves and evaluated. Model I, with one extracellular compartment for glucose and first-order unidirectional uptake, failed, indicating that efflux of glucose from the intracellular space could not be ignored. Model II, with first-order exchanges between extracellular and intracellular compartments and sequestration from the latter, was overdefined because unidirectional clearance of glucose was at least five times the blood flow rate and 20 times the net clearance rate. Model III, combining extracellular and intracellular space into one compartment, was superior in its goodness-of-fit to curves and identifiability of parameters. Michaelis-Menten parameters of sequestration were not identifiable. Parameters of the optimal compartmental capillary, convolution integration model were applicable to both the dynamics of injected glucose dilution and the steady-state background arteriovenous difference of glucose. Glucose sequestration followed first-order kinetics between 0 and 7 mM extracellular glucose with an average rate constant of 0.006 s−1 or a clearance of 44 ml/s. The ratio of intracellular to extracellular glucose distribution space was 0.34, which is considerably lower than the expected intracellular volume and suggests an intracellular occlusion compartment with which extracellular glucose rapidly exchanges.

Kinetics of glucose transport in rat muscle: effects of insulin and contractions

1987 ◽  
Vol 253 (1) ◽  
pp. E12-E20 ◽  
Author(s):  
T. Ploug ◽  
H. Galbo ◽  
J. Vinten ◽  
M. Jorgensen ◽  
E. A. Richter
Keyword(s):  
Glucose Transport ◽  
Fiber Type ◽  
Fiber Types ◽  
Simple Diffusion ◽  
Glycogen Repletion ◽  
Gastrocnemius Muscles ◽  
Slow Twitch Fibers ◽  
Fast Twitch ◽  
Kinetics Of ◽  
Red And White Muscles

The effects of insulin and prior muscle contractions, respectively, on 3-O-methylglucose (3-O-MG) transport in skeletal muscle were studied in the perfused rat hindquarter. Initial rates of entry of 3-O-MG in red gastrocnemius, soleus, and white gastrocnemius muscles as a function of perfusate 3-O-MG concentration exhibited Michaelis-Menten kinetics. Uptake by simple diffusion could not be detected. The maximum 3-O-MG transport velocity (Vmax) was increased more by maximum isometric contractions (10- to 40-fold, depending on fiber type) than by insulin (20,000 microU/ml; 3- to 20-fold) in both red and white muscles. The effects of both contractions and insulin were greater in red than in white muscles. In red but not in white muscles, maximum increases in Vmax elicited by contractions and by insulin were additive. Both insulin and contractions decreased the half-saturating substrate concentration for glucose transport (apparent Km) in all three muscles, in fast-twitch fibers from 70 to approximately 7 mM and in slow-twitch fibers from 12 to 7 mM. After contractions, reversal of contraction-induced glucose transport was monoexponential in red fibers, with a half-time of 7 and 15 min in slow- and fast-twitch fibers, respectively. In white muscle, Vmax continued to increase after contractions, reached a plateau after 10 min, and had only decreased 45% after 70 min. In contrast to the prevailing opinion, in all fiber types, reversal of contraction-induced glucose transport took place in the absence of muscle glycogen repletion.

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