NEUROENDOCRINE CELLS IN THE FEMALE UROGENITAL TRACT OF THE PIG, AND THEIR IMMUNOHISTOCHEMICAL CHARACTERIZATION

A systematic search for neuroendocrine (NE) cells in the urogenital or gans of the pig was carried out by means of Linder's argyrophil method and immunohistochemical techniques. The occurrence, distribution and immunohistochemical character of NE cells (paraneurons) were studied i n the vaginal vestibulum, vagina, uterus, oviduct, ovary, urethra, uri nary bladder and ureter. In the vestibular glands paraneurons were fou nd to be the most numerous, while a moderate number of these cells occ urred in the uterine horn and in the urethra. A distinctly smaller num ber of paraneurons was present in the oviduct and only occasional NE c ells were observed in the urinary bladder. Immunohistochemistry was pe rformed by using the peroxidase-antiperoxidase procedure. Different su bpopulations of paraneurons were distinguishable. Chromogranin A-posit ive paraneurons were found in the vestibular glands, uterine horns, ov iducts, urethra and urinary bladder. Somatostatin positivity was obser ved in NE cells of the vestibular gland, uterine hem, oviduct and uret hra. The subpopulation of serotonin-positive paraneurons was present i n the vestibular gland and urethra. Bombesin, vasoactive intestinal po lypeptide, cholecystokinin, substance P, nitric oxide synthase, P-endo rphin, insulin, adrenocorticotropic hormone, oxytocin and thyroid-stim ulating hormone antibodies gave negative reactions in the studied NE c ells.