To ascertain the extent of reactive oxygen and nitrogen species (RONS) within CP in MS, PD, AD and controls cryostat sections were subjected to either immunohistochemistry (with VIP as chromogen) or sequential complex IV (COX) histochemistry/immunohistochemistry (with VIP).
A–D: In MS, NOX1 was diffusely expressed within the epithelium (ai) as well as in stromal cells (aii). In contrast, NOX1 was restricted to discrete epithelial cells in PD, AD and controls (bi–ii, ci–ii, di–ii). Several respiratory deficient cells with faint NOX1 expression were apparent in MS (aiii) whereas the majority of respiratory deficient cells in PD (biii), AD (ciii) and controls (diii) were not positive for NOX1 (see Table 2 for quantitative data). P22phox, MPO and iNOS were not detected within epithelium in any of the four groups (e–l). MPO positive cells were present within stroma and occasionally in blood vessels (i–l). Interestingly, respiratory deficient cells in any of the four groups were not positive for p22phox, MPO or iNOS, also reflected by quantitative data; with percentage of respiratory deficient cells negative for RONS sources being similar to respiratory deficient cell density by COX/SDH histochemistry.