With the objective of evaluating the enzymatic activity of the trypsin in the intestinal content of the bullfrog (Rana catesbeiana Shaw, 1802), 320 animals with average weight of 3.6 grams were distributed in stall-test with temperature and photoperiod controlled. The frogs selected in the post-metamorphic phase were fed commercial extruded diet ad libitum. For 87 days of experiment, 29 collections were performed at intervals varying from one to eight days. The collections of the intestinal content were performed by the desensitization of the frogs in ice and water and subsequent isolation of the small intestine of the same ones. After each collection, all material was frozen in liquid nitrogen and stored in freezer to be later liofilizated. The determination of the activity of the trypsin was accomplished being used benzoil-D, L-arginine p-nitroanilide (D, L-BApNA) as substrate. The activity of the trypsin was registered in the first day of experiment, and the initial phase is marked by the increase of the activity of the trypsin to reach a stability when the animals were still in the imago phase. In the subsequent period until the end of the experiment, it was observed the maintenance of the stability of the activity and specific activity of the trypsin. It can be concluded that bullfrog shows capacity for digestion of protein feedstuff, and in the initial phase the use of diet rich in protein is recommended.
activity enzymatic; bullfrog; digestive enzymes; Rana catesbeiana; trypsin
