Adrenomedullin reduces intracellular calcium concentration in cultured hippocampal neurons.
Sheng Li Xue Bao
; 57(3): 340-5, 2005 Jun 25.
Article
em En
| MEDLINE
| ID: mdl-15968429
ABSTRACT
The effects of adrenomedullin (ADM) on intracellular calcium concentration ([Ca(2+)](i)) were investigated in cultured hippocampal neurons. Changes in [Ca(2+)](i) were detected by laser scanning confocal microscopy using Fluo 3-AM as the calcium fluorescent probe. [Ca(2+)](i) was represented by relative fluorescent intensity. The results showed that (1) ADM (0.01-1.0 micromol/L) decreased the resting [Ca(2+)](i) in a concentration-dependent manner. (2) Calcitonin gene-related peptide receptor antagonist CGRP(8-37) significantly inhibited the effects of ADM. (3) ADM significantly reduced the increase in [Ca(2+)](i) induced by high K(+). (4) ADM markedly inhibited the inositol 1,4,5-trisphosphate (IP(3))-induced increase in [Ca(2+)](i), while did not influence ryanodine-evoked increase in [Ca(2+)](i). These results suggest that ADM reduces [Ca(2+)](i) in cultured hippocampal neurons through suppressing Ca(2+) release from IP(3)-sensitive stores. Although ADM does not alter resting Ca(2+) influx, it significantly suppresses Ca(2+) influx activated by high K(+). These effects may be partly mediated by CGRP receptors. ADM in the CNS may act as a cytoprotective factor in ischemic/hypoxic conditions.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Peptídeos
/
Cálcio
/
Hipocampo
Limite:
Animals
Idioma:
En
Revista:
Sheng Li Xue Bao
Ano de publicação:
2005
Tipo de documento:
Article