A neurotensin-like hexapeptide; highly expressed in the brain and also expressed in the gastrointestinal system and adrenal glands; competitively inhibits neurotensin binding to rat brain synaptic membranes and is more potent in the presence of bestatin (IC50s = 16.7 and 3 nM, respectively); increases the phagocytic function and chemotaxis of murine peritoneal macrophages in a calcium-dependent manner (10 pM); induces hypotension in rats and has contractile activity on guinea pig ilium; elicits hypothermia in rats in a dose- and time-dependent manner (0.05 to 5 ug, i.c.v.); stimulates spontaneous motor activity and increases dopamine metabolism in several brain regions following injection into the rat ventral tegmental area