Biomedical subjects
Publications and source records attributed to A Manilla.
High levels of glutathione transferase activity were measured during the development of the embryos of Bufo bufo including unfertilized eggs. After stage 4 glutathione transferase activity gradually decreased until stage 25 when the minimum was reached. No change in the number of isozymes was noted during development according to isoelectric focusing analysis performed on the cytosolic fractions of selected stages.
The interaction of 5,6-dihydroxyindole, a putative cytotoxic intermediate of melanin synthesis, with model lambda phage DNA has been investigated by using type II restriction endonucleases and CsCl buoyant density centrifugation. As evidenced by agarose gel electrophoresis and density gradient profiles, the 5,6-dihydroxyindole or u.v. treated DNAs, restricted or not, are modified. U.v. irradiation enhances 5,6-dihydroxyindole binding to DNA, but no sequence specific binding was observed. The action of L-3,4-dihydroxyphenylalanine on the restriction patterns of lambda phage DNA was also investigated and the effect appeared smaller, by qualitative evaluation, than that produced by 5,6-dihydroxyindole.
Glutathione peroxidases and glutathione reductase activities are expressed from the early stage of Bufo bufo development. Selenium-dependent and selenium-independent glutathione peroxidase activities fluctuated independently. The activity of selenium-independent was found to be higher than that of selenium-dependent glutathione peroxidase through all stages of development. Glutathione reductase activity, after a slight fall from stage 4 to stage 7, constantly increased up to stage 25.