Immunohistochemical Localization of NOS Isoforms

Three distinct isoforms of nitric oxide synthases (NOS) have so far been identified and cloned (1 ). There are two constitutively expressed NOS—neuronal (n) and endothelial (e), NOS—and one inducible (i) form, iNOS. All three have been demonstrated immunochemically using antibodies raised against purified enzymes or specific-peptide sequences.