| The effect was dose-dependent in the case of spermidine, but not putrescine and spermine. |
| The putrescine and the cadaverine concentrations were higher in the proximal than in the distal part of the intestinal lumen. |
| Because of their positive charges, putrescine, spermidine, and spermine show a high affinity with the acidic constituents of the cell. |
| In plants, putrescine is also produced through an alternative arginine decarboxylase pathway. |
| However, Lefevre et al. found an ion-specific increase in putrescine and tyramine concentrations. |
| Increasing the concentration of putrescine did not enhance identification of the defects caused by this compound. |
