PLGamide characterization and role in osmoregulation in leech brain.
Brain Res Mol Brain Res
; 76(1): 161-9, 2000 Mar 10.
Article
em En
| MEDLINE
| ID: mdl-10719226
ABSTRACT
Neurons immunoreactive to an antiserum specifically directed against the Prolyl-Leucyl-Glycinamide peptide (PLGamide Melanocyte Inhibiting Factor MIF) were detected in the brain of the leech Theromyzon tessulatum. Radioimmunoassay titrations of the PLGamide-like material at different physiological stages of the life cycle indicated a maximal amount at stage 3B, which is correlated to phase of both maximal water uptake and coelomic vitellogenin accumulation. In vivo experiments demonstrate that this cerebral PLGamide-like material is an anti-diuretic factor that would act at stage 3B in order to permit a water uptake leading to water retention allowing coelomic yolk protein accumulation. In brains of the Gnatobdellid leech Hirudo medicinalis and the Pharyngobdellid leech Erpobdella octoculata, anti-PLGamide material was also detected with an amount not differing with the degree of sex maturation of the animals, confirming the link between osmoregulation and ovogenesis in rhynchobdellid leeches. Using a combination of biochemical techniques including high-pressure gel permeation chromatography followed by reversed-phase HPLC on brain extracts and Edman degradation, we demonstrated the presence of an authentic MIF-1 peptide in leech brain. Finally, since in vertebrates MIF-1 belongs to the non-classical opioid peptide family, we studied its binding displacement, in contrast to morphine, on mu-receptors and on nitric oxide (NO) release experiments in leech brain. PLGamide did not bind to mu-alkaloid opioid receptors and did not stimulate NO release.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Equilíbrio Hidroeletrolítico
/
Encéfalo
/
Hormônio Inibidor da Liberação de MSH
Limite:
Animals
Idioma:
En
Revista:
Brain Res Mol Brain Res
Assunto da revista:
BIOLOGIA MOLECULAR
/
CEREBRO
Ano de publicação:
2000
Tipo de documento:
Article
País de afiliação:
França