Rosario R. Trifiletti's Articles: (3)
AbstractBinding activity for the cage convulsant [35S]-tert-butylbicyclophosphorothionate, which appears to label a site closely associated with the chloride ionophore of the GABAA/benzodiazepine receptor complex has been solubilized from rat cerebral cortex using the zwitterionic detergent CHAPS. Of several detergents screened, only CHAPS and CHAPSO were capable of solubilizing the binding activity with good recovery. The pharmacologic specificity of soluble [35S]-tert-butylbicyclophosphorothionate binding is very similar to the membrane state. In both the membrane and soluble state, [35S]-tert-butylbicyclophosphorothionate binding is enhanced by anions which support inhibitory post-synaptic potentials (“Eccles anions”), suggesting that [35S]-t-butylbicyclophosphorothionate may label chloride channels thought to be involved in these potentials. Since this solubilization procedure also preserves GABA and benzodiazepine binding and their regulation by drugs such as barbiturates, purification and isolation of the macromolecular complex including chloride channel and GABA-benzodiazepine sites may be feasible.
AbstractBinding activity for the cage convulsant [35S]-tert-butylbicyclophosphorothionate, which appears to label a site closely associated with the chloride ionophore of the GABAA/benzodiazepine receptor complex has been solubilized from rat cerebral cortex using the zwitterionic detergent CHAPS. Of several detergents screened, only CHAPS and CHAPSO were capable of solubilizing the binding activity with good recovery. The pharmacologic specificity of soluble [35S]-tert-butylbicyclophosphorothionate binding is very similar to the membrane state. In both the membrane and soluble state, [35S]-tert-butylbicyclophosphorothionate binding is enhanced by anions which support inhibitory post-synaptic potentials (“Eccles anions”), suggesting that [35S]-t-butylbicyclophosphorothionate may label chloride channels thought to be involved in these potentials. Since this solubilization procedure also preserves GABA and benzodiazepine binding and their regulation by drugs such as barbiturates, purification and isolation of the macromolecular complex including chloride channel and GABA-benzodiazepine sites may be feasible.
AbstractRecent evidence in primary neuronal cell culture implicates nitric oxide (NO) as a mediator of glutamatergic neurotoxicity acting via N-methyl-D-aspartate (NMDA) receptors. We find that administration of the potent nitric oxide synthetase (NOS) inhibitor NG-nitro-L-arginine (NO-Arg) at 50 mg/kg to 100 mg/kg i.p. to 6-day old Sprague-Dawley rat pups results in prompt and long-lasting in vivo inhibition of NOS. Fifteen hours after administration, NO-Arg produces essentially complete neuroprotection against hypoxic-ischemic in a standard (Rice-Vanucci) model. These results support the hypothesis that NO may play a key mediatory role in brain damage attending focal ischemic stroke.