RESUMO
The effects of moderate and severe degrees of iron deficiency on brain and liver nonhaem iron levels and 5-hydroxytryptamine (serotonin; 5-HT) uptake by synaptic vesicles in vitro were investigated in experimental rats. Data obtained suggested that in both moderate and severe forms of iron deficiency, 5-HT uptake by brain synaptic vesicles is decreased and is accompanied by a reduction in brain and liver nonhaem iron levels. On repletion with iron for 4 weeks, the deficient group of rats showed a normalisation of 5-HT uptake by synaptic vesicles and liver nonhaem iron content, whereas the brain nonhaem iron concentration still showed a significant deficit. The data thus suggest that changes in the uptake of 5-HT by brain synaptic vesicles that accompany iron depletion and repletion are more rapid than changes in the total nonhaem iron concentration in the brain. The observation that 5-HT uptake by brain synaptic vesicles is decreased in iron deficiency suggests a probable role for iron in 5-HT storage in rat brain.
Assuntos
Encéfalo/metabolismo , Deficiências de Ferro , Serotonina/metabolismo , Vesículas Sinápticas/metabolismo , Animais , Transporte Biológico/efeitos dos fármacos , Hemoglobinas/metabolismo , Ferro/farmacologia , Fígado/metabolismo , Masculino , Especificidade de Órgãos , Ratos , Ratos Endogâmicos , Vesículas Sinápticas/efeitos dos fármacosRESUMO
1. The effects of protein-energy malnutrition on brain free amino acids of acidic and neutral groups were investigated in experimental rats. 2. Severe energy restriction did not modify the free amino acid composition of the brain while protein deficiency affected certain amino acids of the brain in opposite directions. Significant decreases in the levels of aspartic acid, threonine and tyrosine were observed in the protein-deficient rats. 3. These changes in brain amino acids appear to be specific to protein deficiency and not affected by energy deficiency.
