Caracterização da união de [đH]GTP-N a membranas sinápticas purificadas de córtex de ratos

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Caracterização da união de [đH]GTP-N a membranas sinápticas purificadas de córtex de ratos

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5-Aminolevulinic acid inhibits [3H] muscimol binding to human and rat brain synaptic membranes

The interaction of 5-aminolevulinic acid (ALA) with GABAA receptors has been proposed to underlie the neurological dysfunctions of ALA-accumulating disorders, such as acute intermittent porphyria. The effects of ALA on [3 H]muscimol binding to human and rat cerebral cortical membranes were compared. ALA (0.1210 mM) significantly inhibited the binding of [ 3 H]muscimol (12 nM), with a similar potency in rat and human membranes (IC50 = 199 vs. 228 µM, respectively). Kinetical analysis revealed that ALA (1 mM) significantly increased the Kd and decreased the Bmax of [3 H]muscimol to both rat (100 and 50%, respectively) and human (200 and 40%, respectively) membranes, indicating a mixed-type inhibition. The similarity in the potency and mechanism of the ALA-induced inhibition of muscimol binding in rat and human membranes indicate that rat studies are useful to evaluate the neurotoxic properties of ALA towards the human GABAergic system, and may help to understand the pathophysiology of porphyria

Efeito do ácido 5'-aminolevulínico sobre a atividade da adenilato ciclase em membranas plasmáticas cerebrais

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Efeito dos nucleotídeos da guanina sobre a captação e a liberação de glutamato por sinaptossomas de córtex de ratos

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Efeito dos nucleotídeos da guanina sobre a captação e a liberação de glutamato por sinaptossomas de córtex de ratos

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