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Updated: Aug 11, 2026
Depletion and Reconstitution of Macrophages in Mice
Published on: August 1, 2012
Peritoneal macrophages of guinea pig possibly lack LTC4 synthetase
Abstract:
Peritoneal cells and adherent cells of mice and rats synthesized LTC4 and LTB4 when stimulated with A23187 in vitro. On the other hand, neither peritoneal cells nor adherent cells of guinea pigs generated LTC4, D4, and E4, but did the lower amounts of LTB4. Only generation of LTB4 was potentiated by simultaneous addition of 10 microM A.A. in this species. Enzyme solutions which were extracted from peritoneal cells of these three species were capable of converting DNCB to a colored product in the presence of glutathione and then these potencies were in the following order; guinea pig greater than mouse greater than rat. On the other hand, the potencies of converting LTA4 to LTC4 in the presence of glutathione were in the following order; mouse greater than rat much greater than guinea pig approximately equal to 0. These results suggest that macrophages of guinea pigs lack "LTC4 synthetase" and also this enzyme is different from usual GSH S-transferases.
Insights
Mice and rats produce leukotriene C4 (LTC4) and leukotriene B4 (LTB4), while guinea pigs primarily produce LTB4. Guinea pig macrophages appear to lack LTC4 synthetase, an enzyme distinct from typical glutathione S-transferases.
Area of Science:
- Biochemistry
- Immunology
- Cell Biology
Background:
- Leukotrienes (LTs) are inflammatory mediators derived from arachidonic acid (AA).
- Different species exhibit varying capacities for LT synthesis.
- Understanding species-specific LT production is crucial for inflammatory disease research.
Purpose of the Study:
- To investigate the in vitro synthesis of leukotrienes by peritoneal cells from mice, rats, and guinea pigs.
- To characterize the enzymatic activities involved in leukotriene metabolism across these species.
- To determine the presence and activity of LTC4 synthetase in different species.
Main Methods:
- Peritoneal cells and adherent cells from mice, rats, and guinea pigs were stimulated with A23187.
- Leukotriene synthesis (LTC4, LTB4) was measured.
- Enzyme activities, including conversion of DNCB and LTA4 to LTC4 in the presence of glutathione, were assessed.
Main Results:
- Mice and rats synthesized both LTC4 and LTB4.
- Guinea pigs produced lower amounts of LTB4 and negligible amounts of LTC4, LTD4, and LTE4.
- Enzyme assays indicated guinea pig macrophages lack functional LTC4 synthetase, differing from typical glutathione S-transferases.
Conclusions:
- Species-specific differences exist in leukotriene synthesis pathways.
- Guinea pig macrophages possess distinct enzymatic machinery, lacking the LTC4 synthetase found in rodents.
- LTC4 synthetase is likely a unique enzyme separate from common glutathione S-transferases.
