Arginine metabolism of human PMNs
. | . | Murine BMDMs . | . | |
|---|---|---|---|---|
. | Human PMNs, no stimulation . | No stimulation . | IL-4 . | |
| Arginase activity (mU/mg protein) | 1005 ± 280 | 39 ± 1.5 | 1944 ± 98 | |
| Arginine | 93.4 ± 2.8 | 88.3 ± 0.8 | 16.2 ± 3.3 | |
| Ornithine | 4.0 ± 2.4 | 2.9 ± 0.2 | 43.9 ± 2.6 | |
| Spermine | 0.3 ± 0.03 | 5.5 ± 0.5 | 20.3 ± 0.4 | |
. | . | Murine BMDMs . | . | |
|---|---|---|---|---|
. | Human PMNs, no stimulation . | No stimulation . | IL-4 . | |
| Arginase activity (mU/mg protein) | 1005 ± 280 | 39 ± 1.5 | 1944 ± 98 | |
| Arginine | 93.4 ± 2.8 | 88.3 ± 0.8 | 16.2 ± 3.3 | |
| Ornithine | 4.0 ± 2.4 | 2.9 ± 0.2 | 43.9 ± 2.6 | |
| Spermine | 0.3 ± 0.03 | 5.5 ± 0.5 | 20.3 ± 0.4 | |
Human PMNs do not metabolize arginine despite constitutive arginase activity. Human PMNs were incubated in 14C-l-arginine-containing medium. After cell lysis, the radioactively labeled metabolic products were analyzed by TLC and quantified by scintillation counting. The values for each compound are expressed as percentage of the total radioactivity measured in triplicate cultures ± SD. As controls, BMDMs were analyzed in parallel. The murine BMDMs were left unstimulated or preincubated with IL-4 to induce arginase activity. Metabolism of l-arginine was then assessed as described for human PMNs. Arginase activity of the various cell populations is also shown.