In:
Canadian Journal of Physiology and Pharmacology, Canadian Science Publishing, Vol. 86, No. 9 ( 2008-09), p. 626-632
Abstract:
In smooth muscle myocytes, agonist-activated release of calcium ions (Ca 2+ ) stored in the sarcoplasmic reticulum (SR) occurs via different but overlapping transduction pathways. Hence, to fully study how SR Ca 2+ channels are activated, the simultaneous activation of different Ca 2+ signals should be separated. In rat duodenum myocytes, we have previously characterized that acetylcholine (ACh) induces Ca 2+ oscillations by binding to its M 2 muscarinic receptor and activating the ryanodine receptor subtype 2. Here, we show that ACh simultaneously evokes a Ca 2+ signal dependent on activation of inositol 1,4,5-trisphosphate (InsP 3 ) receptor subtype 1. A pharmacologic approach, the use of antisense oligonucleotides directed against InsP 3 R1, and the expression of a specific biosensor derived from green-fluorescent protein coupled to the pleckstrin homology domain of phospholipase C, suggested that the InsP 3 R1-dependent Ca 2+ signal is transient and due to a transient synthesis of InsP 3 via M 3 muscarinic receptor. Moreover, we suggest that both M 2 and M 3 signalling pathways are modulating phosphatidylinositol 4,5-bisphosphate and InsP 3 concentration, thus describing closely interacting pathways activated by ACh in duodenum myocytes.
Type of Medium:
Online Resource
ISSN:
0008-4212
,
1205-7541
Language:
English
Publisher:
Canadian Science Publishing
Publication Date:
2008
detail.hit.zdb_id:
2004356-9
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