RESUMO
The effect of hemodialysis on erythrocyte catalase (CAT) activity was studied in chronic renal failure (CRF) patients. This enzyme was analyzed in vitro, and its activity throughout the incubation period was found to be 34% lower than in healthy donors. The influence of Al3+, Cu2+, and Ni2+ on CAT activity in donor's blood (in vitro) is also studied, for short incubation periods at trace levels of 2.5, 0.25, and 0.196 mM, respectively. With Al3+ and Cu2+, there is a decrease in the enzyme activity. With Ni2+, there is at first a similar decrease, followed by a recovery in activity up to control values.
Assuntos
Catalase/sangue , Eritrócitos/enzimologia , Falência Renal Crônica/enzimologia , Metais/farmacologia , Alumínio/farmacologia , Catalase/antagonistas & inibidores , Cobre/farmacologia , Humanos , Níquel/farmacologia , Diálise RenalRESUMO
Plant ribosome-inactivating proteins (RIPs) are inhibitors present in all parts of plants that irreversibly inactivate eukaryotic ribosomes, thus impairing protein synthesis. RIPs are enzymes with N-glycosidase activity on the large rRNA. Their powerful inhibitory activity has been made use of advantageously to construct conjugates with suitable carriers targeted to altered specific cells. RIPs may be used to inhibit replication of both animal and plant viruses. The introduction of genes coding for RIPs into the genome of plants leads to an increase in resistance towards fungal pathogens and viruses. RIPs are important tools for the treatment of cancer and AIDS and for the protection of crop production.