polyamine catabolic process putrescine metabolic process putrescine catabolic process https://github.com/geneontology/go-ontology/issues/31766 MetaCyc:PWY-2 GO:0009447 MetaCyc:PWY-3 MetaCyc:PWY-0 putrescine breakdown The chemical reactions and pathways resulting in the breakdown of putrescine, 1,4-diaminobutane; putrescine is the metabolic precursor of spermidine and spermine. putrescine catabolism MetaCyc:PWY0-1221 biological_process MetaCyc:PUTDEG-PWY putrescine degradation