Measurement of nitric oxide released in the rat heart with an amperometricmicrosensor

Nitric oxide (NO) plays an important role in various physiological processe s, acting either as an intra- and intercellular messenger or as a toxic age nt. The detection and quantification of NO have been accomplished by a vari ety of methodologies. In the present study, real-time production of NO in t he rat heart was continuously measured by using a novel copper-platinum mic roparticle-modified NO electrochemical microsensor. The linearity range of the microsensor is between 8.0x10(-8) and 4.8x10(-6) mol L-1 and the detect ion limit is 3.0 x 10(-8) mol L-1. NO release from the rat heart stimulated by the agonists l-arginine and acetylcholine was observed, and the respons es were decreased by the NO synthase inhibitor L-N-omega-nitroarginine. In addition, the effect of sodium nitroprusside (SNP), a NO donor, was also st udied. SNP increases the concentration of NO in the rat heart. The experime nts showed that electrochemical detection is suitable for detecting and qua ntifying NO in biological systems.