Differential digestive enzymes activities responses upon emersion in crab Neohelice granulata

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

Chascomús

Jornada; XVI Jornadas Anuales de la Sociedad Argentina de Biología; 2014

Sociedad Argentina de Biologia

Studies on responses of various digestive enzymes upon emersion (E) in euryhaline burrowing crabs are lacking. We studied the effect of E on amylase (Amy), maltase (Mal), sucrase (Suc), lipase (Lip) and proteolytic (Prot) activities in hepatopancreas (HP) and on glucose levels in hemolymph (Glu) in N. granulata. Male crabs acclimated (10 days) in 35 ? salinity were immersed for 24 hs before the experiment (to) and then subjected to E for 60 min (t60). Enzyme activities and Glu were measured at to and t60. Digestive enzyme were assayed in supernatant (10000xg 15min) from HP homogenate (4ml buffer 0.1M Tris-HCl, pH 7.4xg HP-1). Amy (µg maltose x min-1 x mg protein-1), Mal and Sac (µg glucose x min-1x mg protein-1), Lip (μmoles pNP x min-1 x mg protein-1), Prot (enzyme units×h-1× mg protein-1) were assayed by hydrolysis of the corresponding substrate in 50mM phosphate 30ºC (Amy); 0.1 M maleate/OHNa 30ºC (Mal and Sac); 50 mM Tris/HCl 50mM 37ºC (Lip), Tris-HCl, 0.1M, 45°C (Prot). Glu (mgxmlHL-1) was determined with commercial Kit. At t60 Amy (56 %) was lower and Sac was higher (89%) that to (to= Amy: 1376; Sac:55). Mal, Lip and Prot did not change. Glu was higher (230%) that t0 (t0:86).The results suggests differential biochemical digestive and metabolic adjustments upon emersion.