VASOPRESSIN/physiology Dotaz Zobrazit nápovědu
The magnocellular vasopressin (AVP) and oxytocin (OT) neurones exhibit specific electrophysiological behaviour, synthesise AVP and OT peptides and secrete them into the neurohypophysial system in response to various physiological stimulations. The activity of these neurones is regulated by the very same peptides released either somato-dendritically or when applied to supraoptic nucleus (SON) preparations in vitro. The AVP and OT, secreted somato-dendritically (i.e. in the SON proper) act through specific autoreceptors, induce distinct Ca(2+) signals and regulate cellular events. Here, we demonstrate that about 70% of freshly isolated individual SON neurones from the adult non-transgenic or transgenic rats bearing AVP (AVP-eGFP) or OT (OT-mRFP1) markers, produce distinct spontaneous [Ca(2+)]i oscillations. In the neurones identified (through specific fluorescence), about 80% of AVP neurones and about 60% of OT neurones exhibited these oscillations. Exposure to AVP triggered [Ca(2+)]i oscillations in silent AVP neurones, or modified the oscillatory pattern in spontaneously active cells. Hyper- and hypo-osmotic stimuli (325 or 275 mOsmol/l) respectively intensified or inhibited spontaneous [Ca(2+)]i dynamics. In rats dehydrated for 3 or 5days almost 90% of neurones displayed spontaneous [Ca(2+)]i oscillations. More than 80% of OT-mRFP1 neurones from 3 to 6-day-lactating rats were oscillatory vs. about 44% (OT-mRFP1 neurones) in virgins. Together, these results unveil for the first time that both AVP and OT neurones maintain, via Ca(2+) signals, their remarkable intrinsic in vivo physiological properties in an isolated condition.
- MeSH
- dehydratace MeSH
- neurony metabolismus MeSH
- nucleus supraopticus metabolismus MeSH
- osmolární koncentrace MeSH
- oxytocin metabolismus MeSH
- potkani Wistar MeSH
- vápník metabolismus MeSH
- vápníková signalizace * MeSH
- vasopresiny metabolismus MeSH
- zelené fluorescenční proteiny metabolismus MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- MeSH
- arginin vasopresin analogy a deriváty metabolismus MeSH
- desmopresin analogy a deriváty fyziologie MeSH
- fyziologie kůže MeSH
- kůže metabolismus MeSH
- melaniny fyziologie metabolismus MeSH
- melanocyty fyziologie metabolismus MeSH
- sodíkové kanály fyziologie MeSH
- vasopresiny fyziologie MeSH
- žáby MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
Acta endocrinologica, ISSN 0300-9750 vol. 121, suppl. 1, 1989
27 s. : tab., grafy ; 24 cm