Effects of protein malnutrition on oxidative status in rat brain.
OBJECTIVE
This study evaluated the effects of protein malnutrition on oxidative status in rat brain areas.


METHODS
We investigated various parameters of oxidative status, free radical content (dichlorofluorescein formation), indexes of damage to lipid (thiobarbituric acid-reactive substances assay), and protein damage (tryptophan and tyrosine content) in addition to total antioxidant reactivity levels and antioxidant enzyme activities of superoxide dismutase, glutathione peroxidase, and catalase in different cerebral regions (cortex, hippocampus, and cerebellum) from rats subjected to prenatal and postnatal protein malnutrition (control 25% casein and protein malnutrition 7% casein).


RESULTS
Protein malnutrition altered various parameters of oxidative stress, especially damage to macromolecules. Free radical content was unchanged by protein malnutrition. There was an increase in levels of thiobarbituric acid-reactive substances, the index of lipid peroxidation, in the cerebellum and cerebral cortex (P < 0.05) from protein-malnourished rats. Moreover, significant decreases in tryptophan and tyrosine in all tested brain structures (P < 0.05) were observed. Catalase activity was significantly decreased in the cerebellum (P < 0.05). In addition, a significant decrease in total antioxidant reactivity levels (P < 0.05) was observed in the cerebral cortex from protein-malnourished rats.


CONCLUSIONS
The present data indicated that protein malnutrition increased oxidative damage to lipids and proteins from the studied brain areas. These results may be an indication of an important mechanism for changes in brain development that are caused by protein malnutrition.
Feoli
Ana M
AM
Departamento de Bioquímica, Programa de Pós-Graduação em Ciências Biológicas-Bioquímica, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
Siqueira
Ionara R
IR
Almeida
Lúcia
L
Tramontina
Ana C
AC
Vanzella
Cláudia
C
Sbaraini
Sabrina
S
Schweigert
Ingrid D
ID
Netto
Carlos A
CA
Perry
Marcos L S
ML
Gonçalves
Carlos A
CA
D000818:Animals; D002374:Catalase / Q000378:metabolism; D002525:Cerebellar Cortex / Q000187:drug effects* / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism*; D004044:Dietary Proteins / Q000008:administration & dosage*; D005609:Free Radicals / Q000032:analysis; D015227:Lipid Peroxidation / Q000187:drug effects; D044342:Malnutrition; D018384:Oxidative Stress / Q000187:drug effects* / Q000502:physiology; D039401:Prenatal Nutritional Physiological Phenomena; D011488:Protein Deficiency / Q000378:metabolism*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis
D004044:Dietary Proteins; D005609:Free Radicals; D017392:Thiobarbituric Acid Reactive Substances; D002374:Catalase