[EN] The distribution of various hydrolytic enzymes was studied in the digestive tracts of the clams, Ruditapes decussatus and Ruditapes philippindrum. The activity of the enzymes, alkaline phosphatase, acid phosphatase. 5'-nucleotidase, glucose-6-phosphatase and adenosinetriphosphatase was evaluated semiquantitatively in unfixed samples cut by a cryomicrotome at -15ºC. No difference between species was observed in the location of the enzymatic activities. However, there was a variation in the intensity of reaction in the different structures of the digestive tract. Alkaline and acid phosphatase activities were strong in the digestive diverticula, glucose-6-phosphatase showed medium activity in the midgut epithelium, 5'-nucleotidase activity was weak in the gastric epithelium and crystalline style, however the ATPase activity at pH = 9.6 was very intense in the midgut epithelium. Total inhibition of alkaline phosphatase and glucose-6-phosphatase occurred with both L-cysteine (1 mM) and L-phenylalanine (50 mM). N-ethylmaleimide (20 mM) partially inhibited alkaline phosphatase and ATPase activities at pH = 9.6. Acid phosphatase activity was partially inhibited with potassium tartrate (10 mM) and totally with sodium fluoride (10 mM) in the epithelium. All enzymatic activities we investigated were inhibited with (HgCl2, 1 mM).

[ES] Se realiza un estudio sobre la distribución de diversas enzimas hidrolíticas en el aparato digestivo de las almejas Ruditapes decussatus and Ruditapes philippindrum. Las actividades enzimáticas fosfatasa alcalina, fosfatasa ácida, 5'-nucleotidasa, glucosa-6-fosfatasa y adenosintrifosfatasa se valoraron semicuantitativamente en muestras sin fijar y cortadas en un criomicrotomo a - 15º C. La localización de las actividades enzimáticas en el aparato digestivo de ambas especies es idéntica. La intensidad de reacción de las actividades enzimáticas en las diferentes estructuras es variable. Asi, las actividades fosfatasa alcalina y ácida se mostraron intensas a nivel de los divertículos digestivos. La glucosa-6-fosfatasa presentó una intensidad mediana en el epitelio del intestino medio. El epitelio del estómago y estilo cristalino mostraron débil actividad 5'-nucleotidasa y la actividad ATPásica se mostró con fuerte intensidad a nivel del epitelio del intestino medio.

5 páginas, 2 figuras, 2 cuadros.

Peer reviewed