Phe-Leu-Phe-Gln-Pro-Gln-Arg-Phe-NH2 (F-8-F-NH2), isolated from bovine brain, is an FMRF-NH2-like peptide with morphine-modulating activity. In the rat, F-8-F-NH2 immunoreactivity (IR) is highly localized in the neurohypophysis. In this study, F-8-F-NH2-IR was studied in the hypothalamo-neurohypophyseal system of an Arg8-vasopressin (AVP)-deficient animal, the Brattleboro (DI) rat, and the normal control Long-Evans (LE) strain. F-8-F-NH2-IR in the DI pituitary is below the level of detection in contrast to that in the LE (0.50 +/- 0.04 pmol/gland). Neuropeptide Y (NPY) levels are increased two-fold in the DI pituitary while AVP levels are below detection. The content of F-8-F-NH2-IR in the hypothalami and spinal cords of DI and LE rats is not statistically different, suggesting that the absence of F-8-F-NH2-IR in the Brattleboro pituitary is not due to a genetic defect in F-8-F-NH2 biosynthesis. The results of this study raise the question whether AVP could be involved in the regulation of F-8-F-NH2 immunoreactivity in the neurohypophysis.
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http://dx.doi.org/10.1016/0196-9781(90)90091-i | DOI Listing |
Endocrinology
October 1993
Laboratory of Biochemical Genetics, National Institute of Mental Health Neuroscience Center, St. Elizabeth's Hospital, Washington, D.C. 20032.
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.
View Article and Find Full Text PDFPeptides
February 1994
Laboratoire de Pharmacodynamie, Faculté de Pharmacie, Université de Bordeaux II, France.
We studied the ability of NPFF, a FMRFamide-like peptide with certain antiopiate properties, to affect the inhibitory effect of morphine on the electrically induced contraction of guinea pig ileum. Neuropeptide FF had no effect when administered alone but reduced morphine inhibition in a noncompetitive manner. Neuropeptide FF also altered the inhibitory effect of opioid peptides as released by an intense electrical stimulation at 10 Hz.
View Article and Find Full Text PDFBrain Res
October 1992
Laboratory of Biochemical Genetics, St. Elizabethans, Washington DC 20032.
Neuropeptide FF (FLFQPQRF-NH2), originally isolated from bovine brain, is an FMRF-NH2-like peptide with morphine-modulating activity. Neuropeptide FF (NPFF) is highly localized in the dorsal spinal cords where there are also specific NPFF binding sites. Furthermore, there have been studies indicating that NPFF may participate in the regulation of pain threshold in the spinal cord.
View Article and Find Full Text PDFPeptides
June 1992
Laboratory of Biochemical Genetics, NIMH Neuroscience Center, St. Elizabeths, Washington, DC 20032.
Previous studies with the Brattleboro rat suggested a possible interaction at the pituitary level between AVP and the neuropeptide, F-8-F-NH2. In order to test this hypothesis, we studied the effect of various osmotic stimuli on neurohypophyseal F-8-F-NH2. In rats drinking 2% NaCl solution for two days, neural lobe AVP and F-8-F-NH2 levels were equally reduced by 87%.
View Article and Find Full Text PDFJ Comp Neurol
May 1991
Department of Anatomy, University of Helsinki, Finland.
Neuropeptide FF, or F8Famide (Phe-Leu-Phe-Gln-Pro-Gln-Arg-Phe-NH2; "morphine-modulating peptide"), isolated from bovine brain, is an FMRF-NH2-like peptide with morphine-modulating effects. Neuropeptide FF (NFF) is highly concentrated in spinal cords of various mammalian species. There is evidence that NFF participates in the modulation of nociceptive mechanisms.
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