[Rice and bean diets increase hepatic and plasmatic activity of gammaglutamyltranspeptidase in young rats]

The effect of feeding rice and bean diets in both hepatic and plasmatic activity of gamma-glutamyltranspeptidase-(GGT-EC 2.3.2.2) activity was evaluated in growing-rats (Experiment A) and mature rats (Experiment B). During 28 days, the animals were fed with isocaloric-diets composed by tree levels of rice, bean or rice-and-bean protein. Similarly with the aproteic group, a significant increase on both the hepatic and plasmatic GGT activity were showed with the lowest levels of protein, when compared with 25% casein control group. This rise was more effective in growing-rats fed on legume-based diets (as bean or rice-and-bean diets), making evident a differential effect of age and an exacerbated effect of the protein restriction with the lowest sulfur amino acids disposal. These alterations suggest a metabolic adaptation of GGT to both the inadequate protein and sulfur-amino acid levels, thus supporting the hypothesis that the Glutathione levels may be reduced by these legume-based diets.