Title

Re-evaluating NADPH-diaphorase histochemistry as an indicator of nitric oxide synthase: an examination of the olfactory system of coho salmon (Oncorhynchus kisutch)

Author Info

Sean C. Lema, University of California - DavisFollow
Gabrielle A. Nevitt, University of California - Davis

Recommended Citation

Postprint version. Published in Neuroscience Letters, Volume 313, Issue 1-2, November 1, 2001, pages 1-4.

NOTE: At the time of publication, the author Sean C. Lema was not yet affiliated with Cal Poly.

The definitive version is available at https://doi.org/10.1016/S0304-3940(01)02223-6.

Abstract

The NADPH-diaphorase (NADPH-d) histochemical technique is commonly used to localize the nitric oxide (NO)-producing enzyme NO synthase (NOS) in neural tissues. In the olfactory tissues of vertebrates, however, NADPH-d staining can be present without the detection of NOS by other methods. We used pharmacological controls to determine whether NADPH-d staining was indicative of NOS in olfactory tissues from coho salmon (Oncorhynchus kisutch). We also compared NADPH-d staining with immunoreactivity to NOS. NADPH-d staining localized to the olfactory epithelium and to the glomerular layer of the olfactory bulb. Two NOS inhibitors, _L-N-nitroarginine and _L-N-methyl-_L-arginine, failed to block this staining, but the less specific flavin-binder, diphenylene iodonium chloride, decreased or eliminated NADPH-d staining in all olfactory tissues. Immunoreactivity to NOS was present in short axon cells of the bulb, but was absent from the epithelium. Our findings show that NADPH-d staining was not representative of NOS in the olfactory tissues of salmon.

Disciplines

Biology

Copyright

2001 Elsevier.