Adrenomedullin reduces intracellular calcium concentration in cultured hippocampal neurons.
- Author:
Shu-Mei JI
1
;
Jian-Mei XUE
;
Chuan WANG
;
Su-Wen SU
;
Rui-Rong HE
Author Information
1. Department of Biomedical Engineering, Yanshan University, Qinhuangdao 066004, China.
- Publication Type:Journal Article
- MeSH:
Adrenomedullin;
Animals;
Animals, Newborn;
Calcitonin Gene-Related Peptide;
metabolism;
Calcium;
metabolism;
Cells, Cultured;
Embryo, Mammalian;
Hippocampus;
cytology;
metabolism;
Inositol 1,4,5-Trisphosphate;
antagonists & inhibitors;
Neurons;
cytology;
metabolism;
Peptides;
pharmacology;
Rats;
Rats, Sprague-Dawley;
Receptors, Calcitonin Gene-Related Peptide;
antagonists & inhibitors;
metabolism
- From:
Acta Physiologica Sinica
2005;57(3):340-345
- CountryChina
- Language:English
-
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.
