Carbohydrase activities in the hepatopancreas of crab Neohelice granulata: differential long-term post-ingesta response under different salinities

ASARO, A.; DEL VALLE, J.C; LÓPEZ MAÑANES, A,A.

Encuentro; XV Annual Meeting Argentine Biology Society; 2013

Studies of possible differential long-term post-ingesta digestive adjustments at the biochemical level under hyper/hypo-regulation in euryhaline crabs are lacking. The aim was to study the effect of salinity on long-term post-ingesta amylase (Amy), maltase (Mal) and sucrase (Suc) activities in hepatopancreas of N. granulata. Male crabs were maintained (10 days) in 35 (osmoconformation), 37 and 10? salinity (S) (hypo and hyperegulation conditions, respectively). Immediately after ingestion (To) and at 24 (t24), 48 (t48) and 72 (t72) h activities in hepatopancreas were determined. The supernatant (10000xg 15min) (homogenate:0.1M Tris-HCl, pH 7.4) (4ml buffer x g of tissue-1) was used. Amy (μg maltose x min-1 x mg protein-1), Mal and Sac (μg glucosa x mg prot-1 x min-1) were assayed by hydrolysis of the corresponding substrate in 50mM phosphate 30ºC (Amy); 0.1 M maleate/OHNa 30ºC (Mal and Sac).In 35?S at t48 and t72 Amy (22,8%;32,7%) and Mal (20,1%;35,8%) were lower than To (To=Amy: 12326± 2798; Mal: 1285±241).In 37 ?S no activity changed. In 10?S Suc was higher (207,7%) at t72 (To:473 ±113) The results suggest differential long-term biochemical digestive adjustments occurring in relation to osmoregulation status.