Real-time measurement of free radical production using specific electrochemical sensors: New insight into the consequences of O2/- and NO flux

Abstract

Direct real-time electrochemical measurements have offered new insight into the importance of free radical interplay in a number of cellular models. Initially the interrelationship between O2 and NO generation in astrocytic, neuronal and mixed astrocytic/neuronal cell populations was examined. Results indicated a novel function for astrocytic nitric oxide synthase (cNOS) in regulating extracellular O2 release and therefore controlling neuronal nitric oxide availability. Further, the pathological consequences of extracellular O2 production on rat astrocytes was assessed. Findings show that extracellular O2 generation initiated the production of NO by glial cells. Other findings facilitated by electrochemical measurements included the characterisation of a novel motor neuron like cell line for its ability to produce O2 and NO in response to extracellular glutamate and AMPA, the interaction of O2 with NO in an animal models of migraine headache and the modulatory effect of α-melanocyte stimulating hormone (α-MSH) on NO production by human epidermal melanocytes.