Banca de QUALIFICAÇÃO: DOUGLAS DONIZETTI RAIMUNDO

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : DOUGLAS DONIZETTI RAIMUNDO
DATE: 21/12/2022
TIME: 09:00
LOCAL: Videoconferência
TITLE:

EVALUATION OF THE EFFECTS OF TREATMENT WITH HIGH DOSES OF FERROUS SULPHATE ON THE HUMAN ERYTHROCYTE MEMBRANE

KEY WORDS:

Ferrous sulfate. Na,K-ATPase. Erythrocytes. Membrane.

PAGES: 57
BIG AREA: Ciências da Saúde
AREA: Farmácia
SUMMARY:

Ferrous sulfate is one of the most used drugs to replace iron stores and cases of poisoning by this metal are relatively common and are often neglected. As iron in excess, coming from ferrous sulfate, manages to penetrate the plasmatic membrane by passive diffusion, intoxication by this metal may occur due to a high dose. As iron is capable of modulating the activity of Na,K-ATPase and this enzyme is involved in the interiorization of iron in cells, this work proposed to investigate the changes induced in the membrane of human erythrocytes and in the enzyme Na,K-ATPase caused by concentrations of ferrous sulfate that simulate real cases of intoxication. Whole blood samples, in EDTA, were collected from healthy volunteers and cytoplasm-free (ghost) membrane preparations were obtained. Ghosts were treated with increasing concentrations of ferrous sulfate (50 µM, 100 µM, 215 µM, 657 µM and 7.23 mM) for 30 minutes at 37 ºC. Whole blood was treated with 215 µM, 657 µM and 7.23 mM for two hours at 4°C. Membrane preparations showed decreased NKA activity and increased levels of hydrogen peroxide compared to the control group. The increase in hydrogen peroxide can be explained due to the characteristic of iron forming free radicals by Fenton or Haber-Weiss reactions and this increase ends up influencing the physical characteristics of the erythrocyte membrane, decreasing the activity of this enzyme that is found throughout of all cell membranes. In relation to intact erythrocytes, treated with iron sulfate for two hours, no changes were observed related to NKA activity, hydrogen peroxide, malondialdehyde levels, Fe³⁺ levels, as well as antioxidant activity. It may be that the antioxidant defenses of the erythrocytes were sufficient to withstand the damage caused by the excess of this metal within two hours. 

BANKING MEMBERS:
Interna - 1544462 - HERICA DE LIMA SANTOS
Presidente - 1526269 - LEANDRO AUGUSTO DE OLIVEIRA BARBOSA
Externa à Instituição - MARIA DAS GRACAS CARVALHO - UFMG