Comparación de actividades enzimáticas clave en hepatopáncreas de Neohelice granulata de planicie de marea y espartillar de la laguna costera de Mar Chiquita (pcia. Bs. As.).

PINONI, S. A. Y LóPEZ MAñANES, A. A.

Buenos Aires

Jornada; XI Jornadas Multidisciplinarias de la Sociedad Argentina de Biología; 2009

Sociedad Argentina de Biología

Biochemical-physiological adjustments allowing distribution of the euryhaline semiterrestrial crab N. granulata in microhabitats with distinct characteristics are unknown. The aim of this work was to carry out a comparative study of proteolytic (Pr), á-amylase (Am) and alkaline phosphatases (AP) activities in the hepatopancreas (HP) of adult males from mudflat (M) and saltmarsh (SM). The supernatant of 10000xg 15 min from a HP homogenate (0.1MTris-HCl pH 7.4) (4 ml buffer x g of tissue-1) was used. Pr activity (units x h-1xmg prot-1 U) was assayed by measuring azocasein hydrolysis (1 % p/v) in 0.1M Tris-HCl, pH 7.5. Am activity was determined by maltose formation from starch (15mgxml-1) (0.05M phosphate buffer, pH 5.2) with DNS reactive. AP activities (µmoles pNPxmin-1xmg prot-1) were determined by measuring pNPP hydrolisis (9.5mM) in 0.1M Tris-HCl, pHs 7.7 and 8.5 (4mM MgSO4) with (LI) and without 16 mM levamisole. LS: difference between both assays. Activities in M were: Pr 2.7±0.6U; Am: 1.2±0.26 mg maltosexmin-1xmg prot-1; AP LI: 68± 31U, y AP LS: 10.2±3.7U. Am and AP LS activities were similar, whereas Pr and AP LI were higher in SM (5.4±0.8 y 351±149 U respectively) than M (n=10, t-test, p<0.05). This differential flexibility at the biochemical level could be related with the distribution of N. granulata in distinct microhabitats of Mar Chiquita lagoon.