0000000000368653
AUTHOR
E Layes
Fixation conditions affect the intensity but not the pattern of NADPH-diaphorase staining as a marker for neuronal nitric oxide synthase in rat olfactory bulb.
NADPH-diaphorase (NADPH-d) is commonly used as a histochemical marker for the neuronal form of the enzyme nitric oxide synthase (NOS). A recent biochemical study showed that in broken-cell preparations NADPH-d activity did not fully represent NOS and that NOS-unrelated NADPH-d activity was suppressed during fixation. Because it is unknown whether fixation also affects NOS-associated NADPH-d activity, we investigated the effects of various widely used fixatives on NADPH-d staining in relation to NOS immunoreactivity, obtained with polyclonal antibodies, in rat olfactory bulb. We found that the intensity of NADPH-d staining associated with NOS, as well as that unrelated to NOS, depends on fi…
NADPH-diaphorase activity of nitric oxide synthase in the olfactory bulb: co-factor specificity and characterization regarding the interrelation to NO formation.
The neuronal form of the enzyme nitric oxide synthase (nNOS) synthesizes the messenger molecule nitric oxide (NO). In addition to NO formation, nNOS exhibits a so-called NADPH-diaphorase (NADPH-d) activity. This study focused on the characterization of NADPH-d activity with regard to NO formation in the rat olfactory bulb. In this area of the brain pronounced staining is localized in discrete populations of neuronal somata and in olfactory glomeruli. Diaphorase staining combined with demonstration of nNOS by polyclonal antibodies revealed that NADPH-d activity of neuron somata is associated with nNOS immunoreactivity. It is concluded that neuron somata exhibit NADPH-d activity of nNOS. NAD…