Measurement of total nitric oxide metabolite (NOx-) levels in vivo

The measurement of the total level of nitric oxide (NO) metabolite (NOx-) by microdialysis has recently been used to assess the production of NO in the in vivo brain [D. Luo, S. Knezevich, S.R. Vincent, N-Methyl-D-aspartate-induced nitric oxide release: an in vivo microdialysis study, Neuroscience, 57 (1993), 897-900; K. Ohta, N. Arai, M. Shibata, J. Hamada, S. Komatsumoto, K. Shimazu, Y. Fukuuchi, A novel in vivo system for consecutive measurement of brain nitric oxide production combined with the microdialysis technique, Neurosci. Lett., 176 (1994), 165-168; K. Shintani, S. Kanba, T. Nakai, K. Sate, G. Yagi, R. Kato, M. Arai, Measurement by in vivo microdialysis of nitric oxide release in the rat cerebellum, J. Psychiatr. Neurosci., 3 (1994), 217-221; H. Togashi, K. Mori, K. Ueno, M. Matsumoto, N. Suda, H. Saito, M. Yoshika, Consecutive evaluation of nitric oxide production after transient cerebral ischemia in the par hippocampus using in vivo brain microdialysis, Neurosci. Lett., 240 (1998), 53-57]. Although several methods are available for detecting NOx- levels in dialysates, these methods are either not sensitive enough or require expensive experimental equipment. The method described herein provides a convenient and sensitive procedure for determining NOx- levels in dialysates. This method is useful for the in vivo study of NO production from various brain regions in various pathological conditions, and can be applied to other tissues. (C) 1999 Elsevier Science B.V. All rights reserved.