Related Experiment Videos
Polyamine metabolism in Pneumocystis carinii
G Y Lipschik1, H Masur, J A Kovacs
1Critical Care Medicine Department, National Institutes of Health, Bethesda, Maryland 20892.
The Journal of Infectious Diseases
|May 1, 1991
Summary
Alpha-difluoromethylornithine (DFMO) shows promise for treating Pneumocystis pneumonia by inhibiting polyamine synthesis. This study provides in vitro evidence supporting DFMO
Area of Science:
- Microbiology
- Biochemistry
- Parasitology
Background:
- Alpha-difluoromethylornithine (DFMO) is clinically used for Pneumocystis pneumonia despite limited in vitro data.
- DFMO targets ornithine decarboxylase, a key enzyme in polyamine biosynthesis.
Purpose of the Study:
- To investigate polyamine metabolism in Pneumocystis carinii.
- To establish an in vitro method for screening antipneumocystis drugs.
Main Methods:
- Analysis of P. carinii extracts for polyamine content and ornithine decarboxylase activity.
- Measurement of [3H]ornithine and [14C]arginine incorporation into polyamines.
- Assessment of drug effects on ornithine incorporation.
Main Results:
- P. carinii contains putrescine and spermidine; spermine likely originates from host cells.
- The organism incorporates ornithine and arginine into polyamines, but lacks detectable ornithine decarboxylase activity.
- Pentamidine, DFMO, and a DFMO analog inhibited ornithine incorporation by up to 86%.
Conclusions:
- The findings provide a scientific rationale for using polyamine synthesis inhibitors against P. carinii pneumonia.
- This study offers a viable in vitro screening method for novel antipneumocystis agents.