Genetically modified (GM) feeding and food safety: evaluation of cell metabolism by enzymatic analysis in rabbits.

Abstract The insertion of new genes can be a useful tool for obtaining specific characteristic which can lead to an improvement of agronomical relevant traits or food quality. Potential toxicological risks of genetically modified (GM) plant as whole food are evaluated in animal studies according to the classical methods used for drugs, including blood and urine chemistry, organ weight and histopathological examination.With the present studies we aimed to evaluate possible adverse health effects of a GM diet by measuring the activity of organ specific enzymes in rabbits. Twenty weaned New Zealand rabbits were equally assigned tocontrol and treated groups. Animals were fed a diet of pelleted concentrate (80%) and soybean meal (20%), from conventional or genetically modified beans, for controls and treated groups, respectively. Aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatine kinase (CK), lactic dehydrogenase (LDH), gamma glutamyltransferase (GGT) and alkaline phosphatase (ALP) were assayed in serum and in homogenates from liver, kidney, heart and skeletal muscle. Enzyme activity was determined spectrophotometrically. The levels of the enzymes in serum did not show significant differences between controls and treated groups, thus suggesting that no adverse effects were induced by GM soybean meal. In contrast, the analysis of the relative enzyme activities in tissues showed significant increases in enzyme levels, particularly of LDH in the treated animals. As depicted in the table, the distribution of LDH isoenzymes showed significant differences between the groups for heart LDH1 and LDH2, kidney LDH1 and liver LDH1 and LDH4.