Neurotensin, a biologically active peptide.

Neurotensin, a tridecapeptide appears to be localized in various parts of the brain and gut. A high affinity binding component of neurotensin to brain membranes, synaptosomes and mast cells has been reported. After peripheral administration the peptide exerts a medley of effects which appear directed mainly to glucose metabolism. In addition, complex vascular effects have also been noted including hypotensin, cyanosis, vasodilation and increased permeability. The peptide may also be associated with inflammatory events. Complex effects upon the secretion of anterior pituitary tropic hormones have been observed.After central administration neurotensin exerts several effects all of which appear to be sufficiently explained by the potent hypothermic action. The resolution of the question of which, if any, of the actions of neurotensin are involved in physiological regulation has not been achieved.