title: No Evidence That RFamide-Related Peptide 3 Directly Modulates LH Secretion in the Ewe.
abstract: The neuropeptide RFamide-related peptide 3 (RFRP-3) has been implicated in the control of gonadotropin secretion in both birds and mammals. However, in mammals, depending on species, sex and photoperiod, inhibitory, excitatory, or no effect of RFRP-3 on the plasma concentration of LH has been reported. In the ewe, treatment with RFRP-3 either reduced LH concentration or had no effect, and treatment with an RFRP-3 receptor antagonist (ie, RF9) resulted in increased concentration of plasma LH. To clarify these conflicting results in the present study, a set of experiments was performed in ewes. Multiple iv injections of RFRP-3 (6 × 50 μg) in ovariectomized ewes had no effect on plasma LH pulsatility. In intact ewes a bolus injection (500 μg) or an injection (250, 500, or 1000 μg) followed by a 4-hour perfusion (250, 500, or 1000 μg · h(-1)) of RFRP-3 had no effect on the LH pulse induced by kisspeptin (6.5 μg). In ovariectomized, estrogen-replaced ewes, the LH surge induced by estradiol benzoate was not modified by a 24-hour perfusion of RFRP-3 (500 μg h(-1)). Finally, although treatment with RF9 induced a robust release of LH, treatment with a more selective RFRP-3 receptor antagonist, GJ14, resulted in no evident increase of LH. In contrast to the inhibitory effect previously suggested, our data are more consistent with the concept that RFRP-3 has no direct effect on LH secretion in ewes and that RF9 effect on LH release is likely not RFRP-3 receptor mediated. Hence, RFRP-3 probably has a minor role on the control of LH secretion in the ewe.
authors: Unité Mixte de Recherche Physiologie de la Reproduction et des Comportements (Institut National de la Recherche Agronomique, Unité Mixte de Recherche 85; Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7247, Université François Rabelais Tours, IFCE) (C.D., K.A., V.R., D.L., J.B.-S., A.C., L.D., M.B.), F-37380 Nouzilly, France; and Centre for Neuroendocrinology and Department of Anatomy (G.A.), University of Otago School of Medical Sciences, Dunedin 9054, New Zealand.
authors: C
authors: C
authors: Decourt
authors: Unité Mixte de Recherche Physiologie de la Reproduction et des Comportements (Institut National de la Recherche Agronomique, Unité Mixte de Recherche 85; Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7247, Université François Rabelais Tours, IFCE) (C.D., K.A., V.R., D.L., J.B.-S., A.C., L.D., M.B.), F-37380 Nouzilly, France; and Centre for Neuroendocrinology and Department of Anatomy (G.A.), University of Otago School of Medical Sciences, Dunedin 9054, New Zealand.
authors: K
authors: K
authors: Anger
authors: Unité Mixte de Recherche Physiologie de la Reproduction et des Comportements (Institut National de la Recherche Agronomique, Unité Mixte de Recherche 85; Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7247, Université François Rabelais Tours, IFCE) (C.D., K.A., V.R., D.L., J.B.-S., A.C., L.D., M.B.), F-37380 Nouzilly, France; and Centre for Neuroendocrinology and Department of Anatomy (G.A.), University of Otago School of Medical Sciences, Dunedin 9054, New Zealand.
authors: V
authors: V
authors: Robert
authors: Unité Mixte de Recherche Physiologie de la Reproduction et des Comportements (Institut National de la Recherche Agronomique, Unité Mixte de Recherche 85; Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7247, Université François Rabelais Tours, IFCE) (C.D., K.A., V.R., D.L., J.B.-S., A.C., L.D., M.B.), F-37380 Nouzilly, France; and Centre for Neuroendocrinology and Department of Anatomy (G.A.), University of Otago School of Medical Sciences, Dunedin 9054, New Zealand.
authors: D
authors: D
authors: Lomet
authors: Unité Mixte de Recherche Physiologie de la Reproduction et des Comportements (Institut National de la Recherche Agronomique, Unité Mixte de Recherche 85; Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7247, Université François Rabelais Tours, IFCE) (C.D., K.A., V.R., D.L., J.B.-S., A.C., L.D., M.B.), F-37380 Nouzilly, France; and Centre for Neuroendocrinology and Department of Anatomy (G.A.), University of Otago School of Medical Sciences, Dunedin 9054, New Zealand.
authors: J
authors: J
authors: Bartzen-Sprauer
authors: Unité Mixte de Recherche Physiologie de la Reproduction et des Comportements (Institut National de la Recherche Agronomique, Unité Mixte de Recherche 85; Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7247, Université François Rabelais Tours, IFCE) (C.D., K.A., V.R., D.L., J.B.-S., A.C., L.D., M.B.), F-37380 Nouzilly, France; and Centre for Neuroendocrinology and Department of Anatomy (G.A.), University of Otago School of Medical Sciences, Dunedin 9054, New Zealand.
authors: A
authors: A
authors: Caraty
authors: Unité Mixte de Recherche Physiologie de la Reproduction et des Comportements (Institut National de la Recherche Agronomique, Unité Mixte de Recherche 85; Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7247, Université François Rabelais Tours, IFCE) (C.D., K.A., V.R., D.L., J.B.-S., A.C., L.D., M.B.), F-37380 Nouzilly, France; and Centre for Neuroendocrinology and Department of Anatomy (G.A.), University of Otago School of Medical Sciences, Dunedin 9054, New Zealand.
authors: L
authors: L
authors: Dufourny
authors: Unité Mixte de Recherche Physiologie de la Reproduction et des Comportements (Institut National de la Recherche Agronomique, Unité Mixte de Recherche 85; Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7247, Université François Rabelais Tours, IFCE) (C.D., K.A., V.R., D.L., J.B.-S., A.C., L.D., M.B.), F-37380 Nouzilly, France; and Centre for Neuroendocrinology and Department of Anatomy (G.A.), University of Otago School of Medical Sciences, Dunedin 9054, New Zealand.
authors: G
authors: G
authors: Anderson
authors: Unité Mixte de Recherche Physiologie de la Reproduction et des Comportements (Institut National de la Recherche Agronomique, Unité Mixte de Recherche 85; Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7247, Université François Rabelais Tours, IFCE) (C.D., K.A., V.R., D.L., J.B.-S., A.C., L.D., M.B.), F-37380 Nouzilly, France; and Centre for Neuroendocrinology and Department of Anatomy (G.A.), University of Otago School of Medical Sciences, Dunedin 9054, New Zealand.
authors: M
authors: M
authors: Beltramo
mesh_terms: D000218:Adamantane / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D003270:Contraceptive Agents / Q000494:pharmacology; D004151:Dipeptides / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004958:Estradiol / Q000031:analogs & derivatives / Q000494:pharmacology; D005260:Female; D007986:Luteinizing Hormone / Q000097:blood* / Q000378:metabolism*; D009479:Neuropeptides / Q000008:administration & dosage / Q000494:pharmacology*; D010052:Ovariectomy; D011863:Radioimmunoassay; D018013:Receptors, Neuropeptide / Q000037:antagonists & inhibitors / Q000378:metabolism; D012756:Sheep
chemical_list: D003270:Contraceptive Agents; D004151:Dipeptides; D009479:Neuropeptides; C416987:RFamide peptide; D018013:Receptors, Neuropeptide; C508361:adamantylcarbonyl-arginyl-phenylalaninamide; C074283:estradiol 3-benzoate; D004958:Estradiol; D007986:Luteinizing Hormone; D000218:Adamantane