Porphyrin Precursors and Their Effects in vitro on Some Aspects of Nerve Function1

δ‐Aminolaevulinic Acid Uptake, Toxicity, and Effect on [14C]γ‐Aminobutyric Acid Uptake into Neurons and Glia in Culture

“…The degree of inhibition of GABA uptake would appear to be influenced by the particular preparation and experimental conditions employed. ALA at 1 mM concentration inhibited [I4C]GABA uptake into neurons and glia, which is in agreement with previous findings with synaptosomal preparations (Becker et al, 1976;Brennan and Cantrill, 1979~1, but the effect was minimal and was not observed at lower concentrations of ALA. It is unlikely that, in acute porphyria, neural tissue is exposed to sufficiently high levels of ALA to affect reuptake of GABA into neurons or glia.…”

“…It has been suggested that ALA may interfere with the neurotransmitter function of structurally related amino acids, y-aminobutyric acid (GABA) and glutamic acid (Becker et al, 1976). ALA has been shown to inhibit GABA uptake and to increase GABA and glutamate release from rabbit and rat brain cortical synaptosomes (Becker et al, 1976;Brennan and Cantrill, 1979~). ALA has further been shown to reduce the K+-stimulated release of GABA from synaptosomes (Brennan and Cantrill,70 V .…”