Distribution, Characterization, and Growth Hormone-Releasing Activity of Pituitary Adenylate Cyclase-Activating Polypeptide in the European Eel, Anguilla anguilla**This work was supported by grants from INSERM U-413, the Conseil Supérieur de la Pêche, and the Conseil Régional de Haute-Normandie.

• DOI: 10.1210/endo.139.10.6239
• Publication Date: 2014-01-08T16:08:52Z
• Authors: M. Montero; L. Yon; K. Rousseau; A. Arimura; A. Fournier; S. Dufour; H. Vaudry
• Keywords: Diencephalon

The complementary DNA encoding pituitary adenylate cyclase-activating polypeptide (PACAP) has been cloned from two species of teleost fishes, the Sockeye salmon and Thai catfish, amino acid sequence PACAP determined in another teleost, stargazer. However, to date, detailed distribution immunoreactivity never investigated fish brain. In present study, we have localization PACAP-immunoreactive neurons central nervous system a primitive fish, European eel Anguilla anguilla, using an antiserum raised against PACAP27. PACAP-positive perikarya were exclusively observed diencephalon, i.e. preoptic nucleus hypothalamus dorsal ventral nuclei thalamus. fibers detected various areas brain, notably telencephalon, mesencephalon, cerebellar valvula, medulla oblongata. addition, dense accumulation PACAP-containing nerve terminals was found pars distalis pituitary. PACAP-like contained brain characterized by HPLC analysis combined with RIA quantification. major form material coeluted mammalian PACAP38. Molecular cloning precursor previously shown that GH-releasing hormone (GHRH) originate same precursor. We thus effects GHRH on GH secretion cells primary culture. Dose-response experiments revealed PACAP27 PACAP38 possessed efficacy, but 12 times more potent than stimulating release (ED50 = 4.3 × 10−10 3.5 10−9m, respectively). contrast, GHRH, even at high concentration (10−6m), had no effect release. Taken together, these data indicate eel, may play significant role regulation somatotrope cells: 1) are located diencephalon send numerous projections distalis; 2) PACAP, not dose dependently stimulates cultured cells.