Limits...
Differential effects of iodoacetamide and iodoacetate on glycolysis and glutathione metabolism of cultured astrocytes.

Schmidt MM, Dringen R - Front Neuroenergetics (2009)

Bottom Line: However, the two thiol reagents differed substantially in their potential to deprive cellular GSH and to inhibit astrocytic glycolysis.IAA depleted the cellular GSH content more efficiently than IA as demonstrated by half-maximal effects for IAA and IA that were observed at concentrations of about 10 and 100 muM, respectively.In contrast, IA was highly efficient in inactivating GAPDH and lactate production with half-maximal effects observed already at a concentration below 100 muM, whereas IAA had to be applied in 10 times higher concentration to inhibit lactate production by 50%.

View Article: PubMed Central - PubMed

Affiliation: Center for Biomolecular Interactions Bremen, University of Bremen Bremen, Germany.

ABSTRACT
Iodoacetamide (IAA) and iodoacetate (IA) have frequently been used to inhibit glycolysis, since these compounds are known for their ability to irreversibly inhibit the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH). However, the consequences of a treatment with such thiol reagents on the glutathione (GSH) metabolism of brain cells have not been explored. Exposure of astroglia-rich primary cultures to IAA or IA in concentrations of up to 1 mM deprived the cells of GSH, inhibited cellular GAPDH activity, lowered cellular lactate production and caused a delayed cell death that was detectable after 90 min of incubation. However, the two thiol reagents differed substantially in their potential to deprive cellular GSH and to inhibit astrocytic glycolysis. IAA depleted the cellular GSH content more efficiently than IA as demonstrated by half-maximal effects for IAA and IA that were observed at concentrations of about 10 and 100 muM, respectively. In contrast, IA was highly efficient in inactivating GAPDH and lactate production with half-maximal effects observed already at a concentration below 100 muM, whereas IAA had to be applied in 10 times higher concentration to inhibit lactate production by 50%. These substantial differences of IAA and IA to affect GSH content and glycolysis of cultured astrocytes suggest that in order to inhibit astrocytic glycolysis without substantially compromising the cellular GSH metabolism, IA - and not IAA - should be used in low concentrations and/or for short incubation periods.

No MeSH data available.


Related in: MedlinePlus

Disappearance of GSH after exposure to IAA or IA. GSH in a concentration of 10 μM was incubated with the indicated concentrations of IAA (A) or IA (B) for up to 60 min. (C) shows the GSx content that was detected after 60 min incubation with the given concentrations of IAA or IA. The data shown represent mean ± SD of 6 values that were obtained in two independent experiments, each performed in triplicates with individually prepared solutions. The significance of the differences between the values obtained for IAA and IA was calculated by the unpaired t-test and is indicated by #p < 0.05, ##p < 0.01 or ###p < 0.001).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC2691547&req=5

Figure 2: Disappearance of GSH after exposure to IAA or IA. GSH in a concentration of 10 μM was incubated with the indicated concentrations of IAA (A) or IA (B) for up to 60 min. (C) shows the GSx content that was detected after 60 min incubation with the given concentrations of IAA or IA. The data shown represent mean ± SD of 6 values that were obtained in two independent experiments, each performed in triplicates with individually prepared solutions. The significance of the differences between the values obtained for IAA and IA was calculated by the unpaired t-test and is indicated by #p < 0.05, ##p < 0.01 or ###p < 0.001).

Mentions: If not stated otherwise, the data are presented as mean ± SD of values obtained in experiments on three independently prepared cultures. In the figures the bars have been omitted if they were smaller than the symbols representing the mean values. Statistical analysis of the significance of differences between multiple sets of data were performed by ANOVA followed by Bonferroni post hoc test. If not stated otherwise, statistical analysis of the significance of differences between two sets of data was performed using the paired t-test. The data shown in Figure 2 for IAA and IA were obtained separately and were therefore analyzed for significance by the unpaired t-test. p > 0.05 was considered as not significant.


Differential effects of iodoacetamide and iodoacetate on glycolysis and glutathione metabolism of cultured astrocytes.

Schmidt MM, Dringen R - Front Neuroenergetics (2009)

Disappearance of GSH after exposure to IAA or IA. GSH in a concentration of 10 μM was incubated with the indicated concentrations of IAA (A) or IA (B) for up to 60 min. (C) shows the GSx content that was detected after 60 min incubation with the given concentrations of IAA or IA. The data shown represent mean ± SD of 6 values that were obtained in two independent experiments, each performed in triplicates with individually prepared solutions. The significance of the differences between the values obtained for IAA and IA was calculated by the unpaired t-test and is indicated by #p < 0.05, ##p < 0.01 or ###p < 0.001).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2691547&req=5

Figure 2: Disappearance of GSH after exposure to IAA or IA. GSH in a concentration of 10 μM was incubated with the indicated concentrations of IAA (A) or IA (B) for up to 60 min. (C) shows the GSx content that was detected after 60 min incubation with the given concentrations of IAA or IA. The data shown represent mean ± SD of 6 values that were obtained in two independent experiments, each performed in triplicates with individually prepared solutions. The significance of the differences between the values obtained for IAA and IA was calculated by the unpaired t-test and is indicated by #p < 0.05, ##p < 0.01 or ###p < 0.001).
Mentions: If not stated otherwise, the data are presented as mean ± SD of values obtained in experiments on three independently prepared cultures. In the figures the bars have been omitted if they were smaller than the symbols representing the mean values. Statistical analysis of the significance of differences between multiple sets of data were performed by ANOVA followed by Bonferroni post hoc test. If not stated otherwise, statistical analysis of the significance of differences between two sets of data was performed using the paired t-test. The data shown in Figure 2 for IAA and IA were obtained separately and were therefore analyzed for significance by the unpaired t-test. p > 0.05 was considered as not significant.

Bottom Line: However, the two thiol reagents differed substantially in their potential to deprive cellular GSH and to inhibit astrocytic glycolysis.IAA depleted the cellular GSH content more efficiently than IA as demonstrated by half-maximal effects for IAA and IA that were observed at concentrations of about 10 and 100 muM, respectively.In contrast, IA was highly efficient in inactivating GAPDH and lactate production with half-maximal effects observed already at a concentration below 100 muM, whereas IAA had to be applied in 10 times higher concentration to inhibit lactate production by 50%.

View Article: PubMed Central - PubMed

Affiliation: Center for Biomolecular Interactions Bremen, University of Bremen Bremen, Germany.

ABSTRACT
Iodoacetamide (IAA) and iodoacetate (IA) have frequently been used to inhibit glycolysis, since these compounds are known for their ability to irreversibly inhibit the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH). However, the consequences of a treatment with such thiol reagents on the glutathione (GSH) metabolism of brain cells have not been explored. Exposure of astroglia-rich primary cultures to IAA or IA in concentrations of up to 1 mM deprived the cells of GSH, inhibited cellular GAPDH activity, lowered cellular lactate production and caused a delayed cell death that was detectable after 90 min of incubation. However, the two thiol reagents differed substantially in their potential to deprive cellular GSH and to inhibit astrocytic glycolysis. IAA depleted the cellular GSH content more efficiently than IA as demonstrated by half-maximal effects for IAA and IA that were observed at concentrations of about 10 and 100 muM, respectively. In contrast, IA was highly efficient in inactivating GAPDH and lactate production with half-maximal effects observed already at a concentration below 100 muM, whereas IAA had to be applied in 10 times higher concentration to inhibit lactate production by 50%. These substantial differences of IAA and IA to affect GSH content and glycolysis of cultured astrocytes suggest that in order to inhibit astrocytic glycolysis without substantially compromising the cellular GSH metabolism, IA - and not IAA - should be used in low concentrations and/or for short incubation periods.

No MeSH data available.


Related in: MedlinePlus