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Updated: Jun 26, 2026
Depletion and Reconstitution of Macrophages in Mice
Published on: August 1, 2012
Effect of oxidized dextrans on NO synthase and arginase activities of mouse macrophages
V O Tkachev1, O P Kolesnikova, A V Troitskii
1Research Center of Clinical and Experimental Medicine, Siberian Division of the Russian Academy of Medical Sciences, Novosibirsk, Russia. tkachev_victor@gorodok.net
Abstract:
We studied the effect of oxidized dextrans with molecular weights of 30-35 kDa and 60-65 kDa on NO synthase and arginase activities of mouse peritoneal macrophages in vivo and in vitro. Oxidized dextrans irrespective of molecular weight shifted the NO synthase/arginase balance towards predominance of NO production under in vivo and in vitro conditions. Administration of the test compounds to intact mice considerably increased NO synthase activity, while culturing of peritoneal macrophages in the presence of modified dextrans reduced arginase activity in these cells. These effects of oxidized dextrans create conditions for predominant stimulation of Th1-mediated immune reactions.
Insights
Oxidized dextrans enhance nitric oxide (NO) production by shifting the NO synthase/arginase balance. This immune modulation favors Th1 responses in both living mice and cell cultures.
Area of Science:
- Immunology
- Biochemistry
- Materials Science
Background:
- The balance between NO synthase (NOS) and arginase activity is crucial for regulating immune responses.
- Modulating this balance can influence T-helper cell differentiation and overall immune outcomes.
Purpose of the Study:
- To investigate the impact of oxidized dextrans on NO synthase and arginase activities.
- To determine how oxidized dextrans affect the NO synthase/arginase balance in macrophages.
- To assess the potential of oxidized dextrans in modulating immune reactions.
Main Methods:
- In vivo administration of oxidized dextrans (30-35 kDa and 60-65 kDa) to mice.
- In vitro culturing of mouse peritoneal macrophages with oxidized dextrans.
- Assay of NO synthase and arginase activities in macrophages.
Main Results:
- Oxidized dextrans, regardless of molecular weight, promoted a shift towards NO production.
- In vivo, oxidized dextrans significantly increased NO synthase activity.
- In vitro, oxidized dextrans reduced arginase activity in macrophages.
Conclusions:
- Oxidized dextrans effectively alter the NO synthase/arginase balance, favoring NO production.
- These modifications create conditions conducive to the stimulation of Th1-mediated immune responses.
- Oxidized dextrans represent a potential tool for immunomodulation.
