Demonstration of gastrin/cholecystokinin-like immunoreactivity in the arcuate nucleus, median eminence and pituitary of the guinea pig.

In the brains of colchicine-treated guinea pigs, antibodies directed against the C-terminal sequence of cholecystokinin octapeptide (CCK-8) and cross-reacting with gastrin, visualized a dense population of cell bodies in the arcuate nucleus, periportal nerve endings in the external layer of the median eminence and a few fibers in the neurohypophysis. In the adenohypophysis, at least the major part of corticomelanotrophs were labelled. Immunostainings are compared to those reported in the rat.