Alpha‐melanocyte‐stimulating hormone (α‐MSH) in the brain of the African lungfish, Protopterus annectens: Immunohistochemical localization and biochemical characterization

Medientyp: E-Artikel

Titel: Alpha‐melanocyte‐stimulating hormone (α‐MSH) in the brain of the African lungfish, Protopterus annectens: Immunohistochemical localization and biochemical characterization

Beteiligte: Vallarino, Mauro; Bunel, Denis Tranchand; Vaudry, Hubert

Erschienen: Wiley, 1992

Sprache: Englisch

DOI: 10.1002/cne.903220212

ISSN: 0021-9967; 1096-9861

Schlagwörter: General Neuroscience

Entstehung:

Anmerkungen:

Beschreibung: AbstractThe distribution of alpha‐melanocyte‐stimulating hormone (α‐MSH) containing neurons and the molecular forms of α‐MSH‐related peptides exhibit substantial differences in the brains of fish and amphibians. Lungfishes, which share similarities with both fishes and tetrapods, represent a valuable group in which to investigate the neuroanatomical and neurochemical facets of evolution. In the present study, we have localized and characterized α‐MSH‐immunoreactive peptides in the central nervous system of the African lungfish Protopterus annectens. Perikarya exhibiting α‐MSH‐like immunoreactivity were observed in two distinct regions of the hypothalamus: the rostral part of the preoptic nucleus and the caudal part of the hypothalamus. In the caudal hypothalamus most α‐MSH‐immunopositive perikarya were located in both the subependymal and deepest layers of the ventral periventricular region. Scattered α‐MSH‐immunopositive cells were occasionally detected in the dorsal side of the caudal hypothalamus. The α‐MSH‐immunoreactive material localized in the brain was characterized by combining high‐performance liquid chromatography (HPLC) analysis and radioimmunological detection. The displacement curves obtained with synthetic α‐MSH and serial dilutions of brain and pituitary extracts were parallel. HPLC analysis of lungfish hypothalamic extracts showed that the major immunoreactive peak coeluted with synthetic desacetyl α‐MSH and its sulfoxide derivative. An additional peak coeluted with synthetic sulfoxide α‐MSH. In contrast, in the pituitary, the predominant form of α‐MSH‐like material coeluted with the N,O‐diacetyl α‐MSH standard. These results provide the first evidence for the presence of α‐MSH‐related peptides in the brain of a lungfish. The distribution of α‐MSH neuronal systems in the lungfish is very similar to that reported in amphibians, supporting the existence of phylogenetic convergences between these two vertebrate groups. © 1992 Wiley‐Liss, Inc.

Nur in Feld suchen:

Zuletzt gesuchte Begriffe: