”Lipase activity in the hepatopancreas of the euryhaline crab Neohelice granulata: short and long term postfeeding response”

MENDEZ, E.; LÓPEZ MAÑANES, A.A.; PINONI,S.A.

Encuentro; XXVII Annual Scientific Meeting Tucumán Biology Association,; 2010

The modulation of key digestive enzymes activities after feeding in euryhaline crabs is still unknown. The aim of this work was to determine lipase activity in the hepatopancreas (HP) of N. granulata at different times after feeding (AF). Adult male crabs from Mar Chiquita lagoon (Bs. As. Province) were acclimated for 10 days (d) upon salinity (10‰), photoperiod (12 h) and feeding (three times a week; Wadly, 0.07gxind-1) controlled conditions and then starved for 5 d before experiments (pre-ingestion, PI). After this period, crabs were fed and lipase activity was determined immediately (t0), and at 1, 8, 24, 48, 72 and 120 h AF. The supernatant (10000xg 15min) from a HP homogenate (0.1 M Tris-HCl, pH 7.4; 4ml x g of tissue-1) was used. Lipase activity (μmol pNPxmin-1xmg prt-1) was assayed by measuring the hydrolysis of 0.7 mM pNPpalmitate in Tris-HCl 0.05M pH 8.5. PI (28.3±7.1) and t0 (33.6±7.2) activities were similar and lower at 1h AF (8.6±2.8). In the long term (8- 120h), the activity was higher than at 1h, but similar to PI and t0 values (8h:25.2±5.3, 24h:41.9±8.4, 48h:36.3±4.4, 72h:21.6±1.9, 120h:18.2±0.9; n=3, ANOVA, p