Distribution of neurotensin-like immunoreactivity in the hypothalamus, pituitary gland, and gastro-intestinal tract of rats.

The distribution of neurotensin-like immunoreactivity (NTLI) in the pituitary gland, hypothalamus, and throughout the gastro-intestinal tract of adult rats was determined by radioimmunoassay (RIA). NTLI concentrations were higher in the hypothalamus than in the pituitary gland or gastro-intestinal tract. The anterior and posterior pituitary gland had almost the same concentration of NTLI. In the gastro-intestinal tract, the mucosal layer of the small intestine had abundant NTLI. The mucosal layer had higher NTLI levels than the muscular layer throughout the alimentary tract.