[Localization of NADPH-d positive cells in the thymus of pheasants and mice].

The presented study was designed to clarify the localization and distribution of nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) activity, a marker of NO synthase, in pheasant and mouse thymuses. To provide a morphological basis for understanding the role of nitric oxide (NO) in the thymus. The NADPH-d histochemistry revealed dark blue stained cell structures. In the pheasant thymus, NADPH-d positive cells were present as clusters which were distributed in the medulla and the corticomedullar area. NADPH-d positive cells were observed mostly in the medulla of the mouse thymus. They were round, oval or irregular in shape, with various intensity of staining. There were found NADPH-d positive nerve fibres in the perivascular location in both groups of experimental animals. (Fig. 4, Ref. 14.)