Polyamine oxidase and tissue transglutaminase activation in rat small intestine by polyamines

Polyamine degradation was studied in the small intestine from rats fed on a polyamine-supplemented diet. Lactalbumin diet was given to Hooded-Lister r ats, with or without 5 mg rat(-1) day(-1) of putrescine or spermidine for 5 days. Polyamine oxidase activity increased with putrescine and spermidine in the diet, whereas spermidine/spermine N-1-acetyltransferase and diamine oxidase activities were unchanged. We also studied the calcium-dependent an d -independent tissue transglutaminase activities, since they can modulate intestinal polyamine levels. Both types of enzymes increased in the cytosol ic fraction after putrescine (about 65%) or spermidine (80-100%). Our resul ts indicate that exogenous polyamines stimulate intestinal polyamine oxidas e and tissue transglutaminase activities, probably to prevent polyamine acc umulation, when other pathways of polyamine catabolism (acetylation and ter minal. catabolism) are not activated. (C) 1999 Elsevier Science B.V. All ri ghts reserved.