Lysophospholipids Attenuate Acetylcholine-evoked Ca2+ Responses in Bovine Chromaffin Cells
Resource
Taiwania, 55(1), 060-066
Journal
Taiwania
Journal Volume
55
Journal Issue
1
Pages
060-066
Date Issued
2010-03
Date
2010-03
Author(s)
Li-Long Lu
Abstract
Adrenal medulla chromaffin cells are stimulated by acetylcholine released from sympathetic preganglionic neurons and secret catecholamines into the blood to accommodate short-term stress. Acetylcholine activates nicotinic and muscarinic receptors to elevate the intracellular Ca2+ concentration and causes the secretion of catecholamines. Lysophospholipids in the serum, including sphingosine 1-phosphate (S1P) and lysophosphatidic acid (LPA), are released primarily from immune cells during blood clotting and infection to modulate various physiological activities. To characterize the effects of lysophospholipids on Ca2+ responses in bovine chromaffin cells, cells were loaded with the Ca2+ indicator fura-2, and fluorescence intensity was used to monitor changes in intracellular Ca2+ concentration. Cells treated with 1 μM S1P or LPA for 0, 10, 20, 30, 40, 50, or 60 min were stimulated with acetylcholine (100 μM), muscarine (100 μM), DMPP (10 μM), or high K+ buffer (50 mM KCl) for 5 sec. The results showed that the Ca2+ responses evoked by acetylcholine were significantly inhibited after incubation in LPA or S1P for 20 min. The Ca2+ response evoked by high K+ buffer was not inhibited by S1P pretreatment and was significantly facilitated by LPA pretreatment. Muscarine-evoked Ca2+ responses were slightly attenuated by LPA and S1P pretreatments. Nicotine-evoked responses were inhibited in both LPA- and S1P-pretreated cells. Our findings demonstrate that nicotinic receptors may be the main targets of lysophospholipids in inhibiting acetylcholine-evoked Ca2+ responses.
Subjects
Ca2+ channel
G-protein-coupled receptor
lysophosphatidic acid
muscarinic receptor
nicotinic receptor
sphingosine 1-phosphate
鈣離子通道
G蛋白連結受器
水解磷酸脂
蕈毒鹼受器
尼古丁受器
鞘胺醇 1-磷酸鹽
Type
journal article
File(s)![Thumbnail Image]()
Loading...
Name
5501_201003_9.pdf
Size
4 MB
Format
Adobe PDF
Checksum
(MD5):e2645465eb5f9de6557bd32bd13e8020