scholarly journals The permeability of rat liver lysosomes to sugars. Evidence for carrier-mediated facilitated diffusion

1979 ◽  
Vol 178 (2) ◽  
pp. 361-366 ◽  
Author(s):  
K Docherty ◽  
G V Brenchley ◽  
C N Hales
Keyword(s):  
Rat Liver ◽  
Sugar Uptake ◽  
Facilitated Diffusion ◽  
Rate Difference ◽  
Temperature Range ◽  
Lysosomal Membranes ◽  
Sugar Specificity ◽  
Protection Method ◽  
Liver Lysosomes ◽  
Rat Liver Lysosomes

1. By the osmotic-protection method, the penetration of sugars through the rat liver lysosomal membranes was studied with a view of determining whether sugar uptake was by facilitated diffusion. 2. The following criteria for this type of transport were established: sugar specificity, the order of uptake being 2-deoxy-D-glucose less than D-glucose less than D-mannose less than D-galactose less than D-ribose less than 2-deoxy-D-ribose; stereospecificity, the uptake of L-glucose and L-ribose being 50% slower than their D-stereoisomers; inhibition by 1 MM-phlorrhizin and 1 M-cytochalastin B; competition between sugars for uptake, and a Q10 (rate difference over a 10 degrees C temperature range) for uptake of approx. 2.8. 3. It is proposed that sugar uptake into lysosomes from rat liver is by facilitated diffusion.

scholarly journals Sugar transport in rat liver lysosomes. Direct demonstration by using labelled sugars

1983 ◽  
Vol 212 (1) ◽  
pp. 211-218 ◽  
Author(s):  
G A Maguire ◽  
K Docherty ◽  
C N Hales
Keyword(s):  
Rat Liver ◽  
Sugar Transport ◽  
Sugar Uptake ◽  
Facilitated Diffusion ◽  
Direct Demonstration ◽  
Crude Preparation ◽  
Liver Lysosomes ◽  
Net Uptake ◽  
Rat Liver Lysosomes ◽  
Water Space

Purified rat liver lysosomes (‘tritosomes’) were prepared from rats injected with Triton WR-1339. 2. The water space of tritosomes, measured by using [3H]water and [14C]sucrose, was 2.15 +/- 0.72 microliter/mg of protein (mean +/- S.E.M., n = 12). 3. Tritosomes, when compared with a crude preparation of normal lysosomes by an indirect method of study, showed sugar specificity but decreased stereospecificity of sugar uptake. 4. At 125 mM the relative rates of net uptake of D-[14C]ribose, D-[14C]- or D-[3H]glucose and 2-deoxy-D-[3H]glucose were the same as that inferred from the indirect study. 5. The entry of D-[3H]glucose into tritosomes showed concentration-dependence suggestive of saturation, with a Km of 48 +/- 18 mM (4). 6. D- and L-glucose, D-ribose, 2-deoxy-D-glucose and D-mannose competed with D-[14C]glucose or D-[14C]ribose for uptake. 7. Cytochalasin B inhibited D-[3H]glucose uptake. 8. Uptake of 1 mM-L-[14C]glucose was slower than for 1 mM-D-[14C]glucose. 9. It is concluded that a facilitated-diffusion transport system is present in purified rat liver lysosomes.

scholarly journals Passive diffusion of non-electrolytes across the lysosome membrane

1989 ◽  
Vol 261 (2) ◽  
pp. 451-456 ◽  
Author(s):  
G P Iveson ◽  
S J Bird ◽  
J B Lloyd
Keyword(s):  
Hydrogen Bonding ◽  
Rat Liver ◽  
Liver Homogenate ◽  
Inverse Correlation ◽  
Protection Method ◽  
Liver Lysosomes ◽  
Rat Liver Lysosomes ◽  
Lysosome Membrane ◽  
Free Activity

An osmotic-protection method has been used to study the permeability of rat liver lysosomes to 43 organic non-electrolytes of formula weights ranging from 62 to 1000. A lysosome-rich centrifugal fraction of rat liver homogenate was resuspended in an unbuffered 0.25 M solution of test solute, pH 7.0, and incubated at 25 degrees C for 60 min. The free and total activities of 4-methylumbelliferyl N-acetyl-beta-D-glucosaminidase were measured after incubation for 0, 30 and 60 min. Three patterns of results were seen. In pattern A the percentage free activity remained low throughout the 60 min incubation, indicating little or no solute entry into the lysosomes. In pattern B, the percentage free activity was initially low, but rose substantially during the incubation, indicating solute entry. In pattern C there was not even initial osmotic protection, indicating very rapid solute entry. The rapidity of solute entry into the lysosomes showed no correlation with the formula weight, but a perfect inverse correlation with the hydrogen-bonding capacity of the solutes. The results, which can be used to predict the ability of further compounds to cross the lysosome membrane by unassisted diffusion, are discussed in the context of metabolite and drug release from lysosomes in vivo.

Evidence for Facilitated Diffusion of Sugars in Rat Liver Lysosomes

1979 ◽  
Vol 7 (2) ◽  
pp. 364-365 ◽  
Author(s):  
KEVIN DOCHERTY ◽  
GERALD V. BRENCHLEY ◽  
C. NICHOLAS HALES
Keyword(s):  
Rat Liver ◽  
Facilitated Diffusion ◽  
Liver Lysosomes ◽  
Rat Liver Lysosomes

scholarly journals Genistein inhibits glucose and sulphate transport in isolated rat liver lysosomes

2009 ◽  
Vol 103 (2) ◽  
pp. 197-205 ◽  
Author(s):  
Hsu-Fang Chou ◽  
Kun-Hung Chuang ◽  
Yi-Shan Tsai ◽  
Yi-Ju Chen
Keyword(s):  
Glucose Uptake ◽  
Glucose Transport ◽  
Rat Liver ◽  
Uptake Kinetics ◽  
Isolated Rat Liver ◽  
Sulphate Transport ◽  
Genistein Treatment ◽  
Liver Lysosomes ◽  
Rat Liver Lysosomes ◽  
Isolated Rat

Genistein and daidzein are known to have both beneficial and adverse effects on human health due to their many biological actions at the cellular level. Both isoflavones have been shown to inhibit GLUT-mediated glucose transport across the plasma membrane of mammalian cells. Since lysosomal membrane transport is essential for maintaining cellular homeostasis, the present study examined the effects of genistein and daidzein on glucose and sulphate transport in isolated rat liver lysosomes. Both genistein and daidzein significantly inhibited lysosomal glucose uptake. Genistein was a more potent glucose transport inhibitor than daidzein, with a half-maximum inhibitory concentration (IC50) of 45 μmol/l compared with 71 μmol/l for daidzein. Uptake kinetics of d-glucose showed a significant decrease in Vmax (control:genistein treat = 1489 (sem 91):507 (sem 76) pmol/unit of β-hexosaminidase per 15 s) without a change in Km. The presence of 50 μm-genistein in the medium also reduced glucose efflux from lysosomes preloaded with 100 mm-d-glucose. Genistein also inhibited lysosomal sulphate transport. Similar to its effects on glucose uptake kinetics, genistein treatment caused a significant decrease in sulphate uptake Vmax (control:genistein treat = 87 (sem 4):59 (sem 5) pmol/unit of β-hexosaminidase per 30 s), while the Km was not affected. The evidence provided by the present study suggests that the most likely mechanism of lysosomal glucose transport inhibition by genistein is via direct interaction between genistein and the transporter, rather than mediation by tyrosine kinase inactivation. Genistein likely has a similar mechanism of directly inhibiting sulphate transporter.

Pharmacologic perturbation of rat liver lysosomes: Effects on release of lysosomal enzymes and of lipids into bile

1988 ◽  
Vol 95 (4) ◽  
pp. 1088-1098 ◽  
Author(s):  
Richard B. Sewell ◽  
Susan A. Grinpukel ◽  
Alan R. Zinsmeister ◽  
Nicholas F. LaRusso
Keyword(s):  
Rat Liver ◽  
Lysosomal Enzymes ◽  
Liver Lysosomes ◽  
Rat Liver Lysosomes

scholarly journals Interaction of salicylates with rat liver lysosomes

1969 ◽  
Vol 115 (5) ◽  
pp. 54P-54P ◽  
Author(s):  
D Robinson ◽  
P Willcox
Keyword(s):  
Rat Liver ◽  
Liver Lysosomes ◽  
Rat Liver Lysosomes
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