Effect of an abrupt change of salinity on carbohydrase activities in the hepatopancreas of crab Neohelice granulata

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

Buenos Aires

Encuentro; First Biology Meeting of the River Plate.; 2012

Studies about possible digestive adjustments associated to salinity change in euryhaline crabs are lacking. The aim was to study the effect of an abrupt salinity change on amylase (Amy), maltase (Mal) and sucrase (Sac) activities in hepatopancreas. Male crabs maintained for 10 days in 37? salinity (S) (hypo-regulation) were transferred (To) to 10?S (hyper-regulation). Amy, Mal and Sac were determined at To and at 2 (T1), 4 (T2) and 24 (T3) h after transfer. Controls: Crabs maintained in 37?S. The supernatant (10000xg 15min) from a hepatopancreas 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) was assayed by hydrolysis of starch in 50mM phosphate 30ºC and Suc and Mal (μg glucosa x mg prot-1 x min-1) by hydrolysis of the corresponding substrate in 0.1 M maleate/ OHNa 30ºC. At T1 and T2, Amy (7885± 1442; 9255 ± 1373), Mal (1187±34; 957±177) and Suc (55±15; 43± 3) were similar to To. At T3, Amy (3174±1476), Mal (310±119) and Suc (18±9) were lower than activities at To (n= 5; Anova, p