Isolation, Primary Structure, and Effects onα -Melanocyte-Stimulating Hormone Release of Frog Neurotensin 1

Laurence Desrues (1) , Marie-Christine Tonon (1) , Jérôme Leprince (2, 1) , Hubert Vaudry (2) , J. Michael Conlon

1 DC2N - Différenciation et communication neuronale et neuroendocrine
2 Neuroendocrinologie cellulaire et moléculaire

Neurotensin (NT) was isolated in pure form from the small intestine of the European green frog, Rana ridibunda, and its primary structure was established as pGlu-Ala-His-Ile-Ser-Lys-Ala-Arg-Arg-Pro-Tyr-Ile-Leu. This sequence contains five amino acid substitutions (Leu2-->Ala, Tyr3-->His, Glu4-->Ile, Asn5-->Ser, and Pro7-->Ala) compared with human NT. A peptide with identical chromatographic properties was identified in an extract of frog brain. Synthetic frog NT produced a concentration-dependent increase in alphaMSH release from perifused frog pars intermedia cells, with an ED50 of 5 x 10(-9) M. A maximum response (276.3 +/- 45.5% above basal release) was produced by a 10(-8) M concentration. Repeated administration of NT to melanotrope cells revealed the occurrence of a rapid and pronounced desensitization mechanism. The data are consistent with a possible role for the peptide as a hypophysiotropic factor in amphibians.

Domaines: Chimie thérapeutique; Interactions cellulaires [q-bio.CB]; Neurobiologie; Pharmacologie

Laurence Desrues, Marie-Christine Tonon, Jérôme Leprince, Hubert Vaudry, J. Michael Conlon. Isolation, Primary Structure, and Effects onα -Melanocyte-Stimulating Hormone Release of Frog Neurotensin 1. Endocrinology, 1998, 139 (10), pp.4140-4146. ⟨10.1210/endo.139.10.6255⟩. ⟨hal-01962694⟩