Metabolism of putrescine to 2-pyrrolidone by rat liver slices.

The metabolism of [14C]putrescine was studied in sliced rat liver in vitro. delta1-Pyrroline and gamma-aminobutyric acid, known metabolic products of putrescine, were found in the medium. However, 2-pyrrolidone was the major product of the metabolism of putrescine secreted into the medium. 2-Pyrrolidone was also synthesized from putrescine by spleen and lung, but not by kidney, brain, heart, or muscle. This is the first demonstration of the synthesis of 2-pyrrolidone in a biological system.