Electrochemical and UV-Vis Spectroscopic Measurements of Nitric Oxide in Fibroblasts and Astrocytes

Abstract

Two complementary analytical methods were applied to measure nitric oxide production in two cell cultures of fibroblasts and astrocytes: UV-vis spectroscopic assay of nitrites based on Griess reaction and direct, electrochemical determination of nitric oxide with use of a 5 mm diameter disk porphyrinic sensor. The nitrite measurement was used in order to get total quantitative information on NO production in a specified time. Application of an electrochemical sensor allowed observation of the dynamics and stabilization of nitric oxide production in real time, in the vicinity of a culture of stimulated cells. In experiments, cell suspension was placed just above the sensor surface or cells were grown directly on the modified electrode. Current curves were recorded after base current stabilization and injection of L-arginine the last remaining cosubstrate in the system. Collected data enabled one to estimate the local concentration of nitric oxide produced in the culture of fibroblasts to be 70 nM.