PERIVASCULAR LOCALIZATION OF NITRIC-OXIDE SYNTHASE IN THE RAT ADENOHYPOPHYSIS - POTENTIAL IMPLICATIONS FOR FUNCTION AND CELL-CELL INTERACTION

The possible localization of nitric oxide (NO) synthase (NOS) in proxi mity to the microvasculature was examined in the rat adenohypophysis u sing immunohistochemistry and nicotinamide adenine dinucleotide phosph ate diaphorase histochemistry. A population of NOS-positive cells was localized in very close contact with the sinusoidal capillaries. The p attern of this perivascular localization was either unicellular, bicel lular or multicellular. These observations suggest that, at least, som e actions of NO in the adenohypophysis can be accounted for by a local regulation of the glandular microvasculature. (C) 1998 Elsevier Scien ce B.V.