Immunohistochemical Localization, Biochemical Characterization, and Biological Activity of Neurotensin in the Frog Adrenal Gland 1

Autor: Sicard, Flavie, Vaudry, Hubert, Braun, Benedicte, Chartrel, Nicolas, Leprince, Jérôme, Conlon, J. Michael, Delarue, Catherine
Přispěvatelé: Neuroendocrinologie cellulaire et moléculaire, Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut National de la Santé et de la Recherche Médicale (INSERM), Institut Fédératif de Recherches Multidisciplinaires sur les Peptides (IFRMP 23), Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre de Lutte Contre le Cancer Henri Becquerel Normandie Rouen (CLCC Henri Becquerel)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Université Le Havre Normandie (ULH), Normandie Université (NU)-CHU Rouen, Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS), Creighton University Medical School [Omaha, NE, USA]
Jazyk: angličtina
Rok vydání: 2000
Předmět:
Zdroj: Endocrinology
Endocrinology, Endocrine Society, 2000, 141 (7), pp.2450-2457. ⟨10.1210/endo.141.7.7544⟩
ISSN: 0013-7227
DOI: 10.1210/endo.141.7.7544⟩
Popis: International audience; The primary structure of neurotensin has been recently determined for the frog Rana ridibunda (Endocrinology 139: 4140-4146, 1998). In the present study, we have investigated the distribution and biochemical characterization of neurotensin-like immunoreactivity in the frog adrenal gland, using an antiserum directed against the conserved C-terminal region of the peptide. Neurotensin-like immunoreactivity was detected in two populations of nerve fibers: numerous varicose fibers coursing between adrenal cells, and a few processes located in the walls of blood vessels irrigating the gland. Reversed-phase HPLC analysis of frog adrenal gland extracts revealed the existence of a major peak of neurotensin-like immunoreactivity that exhibited the same retention time as synthetic frog neurotensin. The possible involvement of neurotensin in the regulation of steroid secretion was studied in vitro using perifused frog adrenal slices. For concentrations ranging from 10(-10) to 10(-5) M, synthetic frog neurotensin increased corticosterone and aldosterone production in a dose-dependent manner (EC50 = 1.2 x 10(-9) M and 5.8 x 10(-10) M, respectively). Repeated administration of neurotensin induced a reproducible stimulation of steroid output without any tachyphylaxis. Prolonged administration (3 h) of frog neurotensin caused a transient increase in corticosterone and aldosterone secretion followed by a decline of corticosteroid secretion. Neurotensin also produced a significant stimulation of corticosteroid secretion from dispersed frog adrenal cells. This study demonstrates that neurotensin is located in nerve processes innervating the adrenal gland of amphibians. The results also show that synthetic frog neurotensin exerts a direct stimulatory effect on corticosteroid output. Taken together, these data support the view that neurotensin, released by nerve fibers, may act as a local regulator of corticosteroid secretion.
Databáze: OpenAIRE