Origin of neurohypophyseal neuropeptide-FF (FLFQPQRF-NH2).

Neuropeptide-FF (FLFQPQRF-NH2), originally isolated from bovine brain, is an FMRF-NH2-like peptide with morphine-modulating activity. Neuropeptide-FF (NPFF) is unevenly distributed in the central nervous system, with the highest concentrations in posterior pituitary and spinal cord. In the rat pituitary, NPFF is found exclusively in the neural lobe, where it is localized in nerve terminals and fibers, indicating the hypothalamus as a possible source of the neural lobe NPFF. In this study the origin of neurohypophyseal NPFF was investigated using various hypothalamic lesions and an anterograde tracing experiment. The results suggest that at least part of the neurohypophyseal NPFF originates from the supraoptic nucleus and may be localized in some of the arginine vasopressin-containing magnocellular neurons.