J E Maddison

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Cerebrocortical [3H]L-glutamate uptake was examined using brain slices and synaptosomes obtained from rats with portal vein and bile duct ligation. In addition, the effect of in vitro addition of 5 mM ammonia on glutamate uptake parameters was determined. There was no significant difference in brain slice or synaptosomal glutamate uptake in rats with portal(More)
Excitatory amino acid receptor binding parameters were investigated in a spontaneous dog model of chronic hepatic encephalopathy. L-[3H]Glutamate, (+)-[3H]-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-im ine maleate ([3H]MK-801), [3H]kainate, and alpha-[3H]-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid ([3H]AMPA) binding experiments were(More)
Fractions and subcellular structures were prepared from rat brain homogenate and their purity was assessed using enzyme markers, gamma-aminobutyric acid binding, DNA content, and electron microscopy. Insulin binding was highest on the plasma membrane preparations and approximately 50% less so on brain homogenate crude mitochondrial (P2), myelinated axon,(More)
Oestrous cycle and sex differences in sodium-dependent transport of L-[3H]glutamate and L-[3H]aspartate were investigated employing well washed synaptosomes prepared from rat brain cortex. Transport was best analysed on the basis of two components, a high and low affinity transport site. Oestrous cycle and sex differences were observed for both substrates.(More)
High affinity [3H]gamma-aminobutyric acid (GABA) and [3H]L-glutamate uptake were determined in synaptosomes prepared from the cerebral cortex of dogs with congenital hepatic encephalopathy and control dogs. The Km value for GABA uptake was increased by 35% but there was a concomitant 34% increase in Vmax suggesting that GABA uptake capacity was not changed(More)
There is increasing evidence that glutamatergic neurotransmission is perturbed in hepatic encephalopathy (HE). Studies of the glutamate receptor system suggest that glutamate receptor density is reduced in different animal models of HE. Glutamate release and/or uptake is also believed to be altered in the disorder resulting in increased glutamate(More)
The pharmacological profile and binding characteristics of the non-NMDA antagonist of glutamate receptors [3H]6-cyano-7-nitro-quinoxaline-2,3-dione (CNQX), were investigated in triton-washed crude synaptosomal membranes prepared from canine cerebral cortex. [3H]CNQX binding was inhibited by various glutamate agonists and antagonists, the rank order of(More)
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