The presence of CCK-containing neuroendocrine cells in human adenomato
us prostates, and the colocalization of CCK together with serotonin in
the same cell, have been demonstrated by means of an immunohistochemi
cal technique and by a double labeling immunofluorescent staining. CCK
-containing neuroendocrine cells had a focal distribution in the prost
ates and sometimes showed dendrite-like cytoplasmic processes. The maj
or part of CCK (96.55%) colocalized with serotonin. CCK probably stimu
lates muscle contraction and endocrine/exocrine secretions in the urog
enital tract.