Neuronal nitric oxide synthase immunohistochemistry and 4,5-diaminofluorescein diacetate: tools for nitric oxide research

Nitric oxide plays an important role in many biological processes including the cardiovascular, immune, reproductive and nervous systems. There is muc h interest surrounding this molecule and the enzyme responsible for its syn thesis, nitric oxide synthase. In order to investigate the role of nitric o xide in various biological processes it is necessary to be able to identify the released molecule itself as well as nitric oxide synthase. Detection o f nitric oxide synthase was achieved by optimisation of the immunohistochem ical localisation of the neuronal isoform of the enzyme in primary cultures of rat ventral mesencephala and in fixed adult rat brain sections. Further more, using 4,5-diaminofluorescein diacetate, we have directly visualised e ndogenously produced nitric oxide in mesencephalic cultures and demonstrate d the potential use of this indicator for visualising nitric oxide produced in vivo. (C) 2001 Elsevier Science B.V. All rights reserved.