A comparative study of antioxidant enzyme activities in tissues of Helix aspersa (O.F.Mull.) and Pomacea bridgesi (Reeve)

Antioxidant enzymes: catalase (CAT) [EC 1.11.1.6], peroxidase [EC 1.11.1.7], glutathione reductase (GSSGR) [EC 1.6.4.2] and glucose-6-phosphate dehydrogenase (G6PDH) [EC 1.1.1.49] were investigated in terrestrial Helix aspersa (O.F. Müll.) and aquatic Pomacea bridgesi (Reeve). The activity was determined in the heamolymph and homogenates of hepatopancreas and foot muscle. No CAT and peroxidase activity was detected in the hepatopancreas and foot muscle of P. bridgesi, and its haemolymph displayed a very low CAT activity (0.005 U/mg of protein). In H. aspersa the highest activities (U/g) observed for CAT and GSSGR in the hepatopancreas were 0.40, and 1.05, respectively; for peroxidase and G6PDH in the foot muscle the respective values were 1.22 and 0.22. The activities of antioxidant enzymes determined in both snail species are much lower than the corresponding values for mammalian tissues

Tissue distribution of glucose-6-phosphatase and fructose-1,6-bisphosphatase in Helix pomatia L. and Pomacea bridgesii (Reeve)

Key enzymes of gluconeogenesis, D-glucose-6-phosphatase (G-6-Pase) [EC 3.1.3.9] and D-fructose-1,6-bisphosphate 1-phosphohydrolase (Fru-1,6-Pase) [EC 3.1.3.11], were investigated in Helix pomatia L. and Pomacea bridgesii (Reeve). Fru-1,6-Pase and G-6-Pase activities were determined measuring with malachite green the concentration of inorganic phosphate produced by substrate hydrolysis in homogenates of hepatopancreas, kidney and foot muscle. Determined Fru- , -Pase activities (U/g wt.) in H. pomatia were as follows: hepatopancreas 1.01, kidney 0.19, foot muscle 0.24, in P. bridgesii the respective values were: 0.94, 0.34 and 0.22. Activities of G-6-Pase (U/g wt.) in H. pomatia were: 1.65 in hepatopancreas, 0.64 in kidney and 0.21 in foot muscle, in P. bridgesii the respective values were: 0.79, 0.31, 0.21. Thus the highest gluconeogenic capacity in both species was found in hepatopancreas. Fru-1,6-Pase from H. pomatia and P. bridgesii hepatopancreas was inhibited by AMP. Determined I0.5 were 8.4 M for H. pomatia and 7.3 M for P. bridgesii, and the values were comparable with those of mammalian liver Fru-1,6-Pase. Km determined for hepatopancreas G-6-Pase from H. pomatia and P. bridgesii were 1.3 mM and 4.1 mM, respectively and were also comparable with Km of mammalian liver enzyme