The C-terminal NPY fragment (13-36) [NPY-(13-36)], a Y2 receptor agonist, elicits vasopressor responses upon central administration. The cardiovascular responses of NPY-(13-36), together with the distribution of NPY receptor subtypes within the nucleus tractus solitarius (nTS), have been studied in spontaneously hypertensive rats (SHR). Neuropeptide Y (13-36) (NPY 13-36) stimulates both Y2 and Y5 NPY receptor subtypes, but causes no increase in food intake even when injected at high doses, while the full-length NPY is one of the most potent physiological stimulants of feeding yet described. NPY 13-16 inhibits retinotectal transfer in amphibians.