The Ca2+ –regulated Exocytosis Enhanced by Arachidonic Acid/PPARα in Guinea– pig Antral Mucous Cells

MEMBRANE ◽  
2015 ◽  
Vol 40 (5) ◽  
pp. 272-277
Author(s):  
Saori Tanaka ◽  
Takashi Nakahari
Keyword(s):  
Arachidonic Acid ◽  
Guinea Pig ◽  
Mucous Cells ◽  
Regulated Exocytosis

Enhancement of Ca2+-regulated exocytosis by indomethacin in guinea-pig antral mucous cells: arachidonic acid accumulation

2005 ◽  
Vol 91 (1) ◽  
pp. 249-259 ◽  
Author(s):  
Shoko Fujiwara ◽  
Chikao Shimamoto ◽  
Yoshihiko Nakanishi ◽  
Ken-ichi Katsu ◽  
Masumi Kato ◽  
...  
Keyword(s):  
Arachidonic Acid ◽  
Guinea Pig ◽  
Mucous Cells ◽  
Regulated Exocytosis ◽  
Acid Accumulation

scholarly journals Peroxisome proliferation activation receptor α modulation of Ca2+-regulated exocytosis via arachidonic acid in guinea-pig antral mucous cells

2010 ◽  
Vol 95 (8) ◽  
pp. 858-868 ◽  
Author(s):  
Yukinori Sawabe ◽  
Chikao Shimamoto ◽  
Akiko Sakai ◽  
Hiroko Kuwabara ◽  
Adel H. Saad ◽  
...  
Keyword(s):  
Arachidonic Acid ◽  
Guinea Pig ◽  
Peroxisome Proliferation ◽  
Mucous Cells ◽  
Regulated Exocytosis

scholarly journals Isosmotic modulation of Ca2+-regulated exocytosis in guinea-pig antral mucous cells: role of cell volume

1999 ◽  
Vol 516 (1) ◽  
pp. 85-100 ◽  
Author(s):  
Shoko Fujiwara ◽  
Chikao Shimamoto ◽  
Ken-ichi Katsu ◽  
Yusuke Imai ◽  
Takashi Nakahari
Keyword(s):  
Guinea Pig ◽  
Cell Volume ◽  
Mucous Cells ◽  
Regulated Exocytosis

[Cl−]i modulation of Ca2+-regulated exocytosis in ACh-stimulated antral mucous cells of guinea pig

2007 ◽  
Vol 293 (4) ◽  
pp. G824-G837 ◽  
Author(s):  
Chikao Shimamoto ◽  
Eiji Umegaki ◽  
Ken-ichi Katsu ◽  
Masumi Kato ◽  
Shoko Fujiwara ◽  
...  
Keyword(s):  
Guinea Pig ◽  
Benzoic Acid ◽  
Dose Response ◽  
Initial Phase ◽  
Channel Blocker ◽  
Atp Depletion ◽  
Mucous Cells ◽  
Response Curves ◽  
Regulated Exocytosis ◽  
Intracellular Ca

The effects of intracellular Cl− concentration ([Cl−]i) on acetylcholine (ACh)-stimulated exocytosis were studied in guinea pig antral mucous cells by video microscopy. ACh activated Ca2+-regulated exocytosis (an initial phase followed by a sustained phase). Bumetanide (20 μM) or a Cl− -free (NO3−) solution enhanced it; in contrast, 5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB, a Cl− channel blocker) decreased it and eliminated the enhancement induced by bumetanide or NO3− solution. ACh and Ca2+ dose-response studies demonstrated that NO3− solution does not shift their dose-response curves, and ATP depletion studies by dinitrophenol or anoxia demonstrated that exposure of NO3− solution prior to ATP depletion induced an enhanced initial phase followed by a sustained phase, whereas exposure of NO3− solution after ATP depletion induced only a sustained phase. Intracellular Ca2+ concentration ([Ca2+]i) measurements showed that bumetanide and NO3− solution enhanced the ACh-stimulated [Ca2+]i increase. Measurements of [Cl−]i revealed that ACh decreases [Cl−]i and that bumetanide and NO3− solution decreased [Cl−]i and enhanced the ACh-evoked [Cl−]i decrease; in contrast, NPPB increased [Cl−]i and inhibited the [Cl−]i decrease induced by ACh, bumetanide, or NO3− solution. These suggest that [Cl−]i modulates [Ca2+]i increase and ATP-dependent priming. In conclusion, a decrease in [Cl−]i accelerates ATP-dependent priming and [Ca2+]i increase, which enhance Ca2+-regulated exocytosis in ACh-stimulated antral mucous cells.

cGMP modulation of ACh-stimulated exocytosis in guinea pig antral mucous cells

2006 ◽  
Vol 290 (6) ◽  
pp. G1138-G1148 ◽  
Author(s):  
Adel H. Saad ◽  
Chikao Shimamoto ◽  
Takashi Nakahari ◽  
Shoko Fujiwara ◽  
Ken-ichi Katsu ◽  
...  
Keyword(s):  
Guinea Pig ◽  
Dose Response ◽  
Response Curve ◽  
Atp Depletion ◽  
Camp Accumulation ◽  
Transient Phase ◽  
Mucous Cells ◽  
Regulated Exocytosis ◽  
Initial Transient ◽  
Curve Upward

In guinea pig antral mucous cells, ACh stimulates the Ca2+-regulated exocytosis, which has a characteristics feature: an initial transient phase followed by a sustained phase. The effects of cGMP on ACh-stimulated exocytosis were studied in guinea pig antral mucous cells using video microscopy. cGMP enhanced the frequency of ACh-stimulated exocytotic events, whereas cGMP alone did not induce any exocytotic events under the ACh-unstimulated condition. cGMP did not stimulate either Ca2+ mobilization or cAMP accumulation. The Ca2+ dose-response studies demonstrated that cGMP shifted the dose-response curve upward with no shift to the lower concentration. This indicates that cGMP increased maximal responsiveness of the Ca2+-regulated exocytosis, but not the Ca2+ sensitivity. Moreover, under a condition of ATP depletion by dinitrophenol (DNP) or anoxia (N2 bubbling), ACh evoked only a sustained phase in exocytotic events with no initial transient phase. However, ACh evoked an initial transient phase followed by a sustained phase with addition of cGMP before ATP depletion, whereas only a sustained phase was evoked in a case of cGMP addition after ATP depletion. Thus cGMP-induced enhancement in ACh-stimulated exocytotic events requires ATP, suggesting that cGMP modulates ATP-dependent priming of Ca2+-regulated exocytosis in antral mucous cells. In conclusion, cGMP increases the number of primed granules via acceleration of the ATP-dependent priming, which enhances the Ca2+-regulated exocytosis stimulated by ACh.

cAMP modulation of Ca2+-regulated exocytosis in ACh-stimulated antral mucous cells of guinea pig

2002 ◽  
Vol 282 (5) ◽  
pp. G844-G856 ◽  
Author(s):  
Takashi Nakahari ◽  
Shoko Fujiwara ◽  
Chikao Shimamoto ◽  
Kumiko Kojima ◽  
Ken-Ichi Katsu ◽  
...  
Keyword(s):  
Guinea Pig ◽  
Dose Response ◽  
Camp Accumulation ◽  
Transient Phase ◽  
Mucous Cells ◽  
Response Curves ◽  
Regulated Exocytosis ◽  
Initial Transient ◽  
Contrast Microscopy ◽  
Two Phases

Effects of cAMP accumulation on ATP-dependent priming and Ca2+-dependent fusion in Ca2+-regulated exocytosis were examined in antral mucous cells of guinea pigs by using video-enhanced contrast microscopy. The Ca2+-regulated exocytosis activated by 1 μM ACh consisted of two phases, an initial transient phase followed by a sustained phase, which were potentiated by cAMP accumulation. Depletion of ATP by 100 μM dinitrophenol (uncoupler of oxidative phosphorylation) or anoxia induced the sustained phase without the initial transient phase in Ca2+-regulated exocytosis. However, accumulation of cAMP before depletion of ATP induced and potentiated an initial transient phase followed by a sustained phase in Ca2+-regulated exocytosis. This suggests that the initial transient phase of Ca2+-regulated exocytosis is induced by fusion of all primed granules maintained by ATP and that accumulation of cAMP accelerates ATP-dependent priming of the exocytotic cycle. Moreover, ACh and Ca2+ dose-response studies showed that accumulation of cAMP shifted the dose-response curves to the low concentration side, suggesting that it increases Ca2+ sensitivity in the fusion of the exocytotic cycle. In conclusion, cAMP accumulation increases the number of primed granules and Ca2+ sensitivity of the fusion, which potentiates Ca2+-regulated exocytosis in antral mucous cells.

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