Differential modulation after feeding in different salinities and response to ABA and extracellular Ca++ of APN activity in hepatopancreas of the intertidal euryhaline crab Neohelice granulata

MICHIELS, M.S.; LÓPEZ MAÑANES, A,A.; DALEO, G.R.

CANADIAN JOURNAL OF ZOOLOGY

NATL RESEARCH COUNCIL CANADA-N R C RESEARCH PRESS

Lugar: Otawa; Año: 2020 vol. 98 p. 262 - 268

0008-4301

Abstract: Modulation of aminopeptidase N (APN) activity in the digestive tract by various factors would be important to adjustdigestive and absorptive processes under different physiological and (or) environmental conditions. We studied the postprandialresponses at different salinities and the effect of abscisic acid (ABA) and extracellular Ca2+ on APN activity in the hepatopancreas(the main site for nutrient digestion and absorption) of the model species Neohelice granulata (Dana, 1851). Enzyme activity wasdetermined at different times (0, 24, 48, and 72 h) after feeding in crabs acclimated either to 35 psu (osmoconformation) or 10 psu(hyper-regulation). APN activity increased around 50% at 24 h after feeding at 35 psu, whereas no changes occurred at 10 psu.Enzyme activity was also assayed in the presence of ABA (1 × 10?4 mol·L?1) or extracellular Ca2+ (1 × 10?4 mol·L?1), showingincrements of 60% and 56%, respectively. The results suggest a role of APN in postprandial adjustments and its modulation bydifferent chemical messengers by direct effect on the hepatopancreas. Moreover, to our knowledge, this work is the first to showthe effect of ABA on a digestive enzyme in the digestive tract of an animal.