scholarly journals Enhancement by KW-5092, a novel gastroprokinetic agent, of the release of acetylcholine from enteric neurons in the guinea pig stomach

1998 ◽  
Vol 76 ◽  
pp. 297
Author(s):  
Nobuyuki Kishibayashi ◽  
Akira Karasawa
1997 ◽  
Vol 273 (5) ◽  
pp. G1044-G1050
Author(s):  
Kazuko Shichijo ◽  
Yasuko Sakurai-Yamashita ◽  
Ichiro Sekine ◽  
Kohtaro Taniyama

Neuronal release of endogenous dopamine was identified in mucosa-free preparations (muscle layer including intramural plexus) from guinea pig stomach corpus by measuring tissue dopamine content and dopamine release and by immunohistochemical methods using a dopamine antiserum. Dopamine content in mucosa-free preparations of guinea pig gastric corpus was one-tenth of norepinephrine content. Electrical transmural stimulation of mucosa-free preparations of gastric corpus increased the release of endogenous dopamine in a frequency-dependent (3–20 Hz) manner. The stimulated release of dopamine was prevented by either removal of external Ca2+ or treatment with tetrodotoxin. Dopamine-immunopositive nerve fibers surrounding choline acetyltransferase-immunopositive ganglion cells were seen in the myenteric plexus of whole mount preparations of gastric corpus even after bilateral transection of the splanchnic nerve proximal to the junction with the vagal nerve (section of nerves between the celiac ganglion and stomach). Domperidone and sulpiride potentiated the stimulated release of acetylcholine and reversed the dopamine-induced inhibition of acetylcholine release from mucosa-free preparations. These results indicate that dopamine is physiologically released from neurons and from possible dopaminergic nerve terminals and regulates cholinergic neuronal activity in the corpus of guinea pig stomach.


1992 ◽  
Vol 263 (5) ◽  
pp. G709-G718 ◽  
Author(s):  
M. Schemann ◽  
D. Grundy

Myenteric "command neurons" are thought to be the interface between extrinsic and intrinsic controls of gut functions and are thought to be responsible for transmission of vagal impulses to enteric microcircuits. To identify, electrophysiologically, myenteric neurons responding to electrical stimulation of the vagus, we developed an in vitro preparation of the gastric myenteric plexus in which the vagal innervation was preserved. The majority of myenteric neurons [102 of 155 (66%)] received fast excitatory postsynaptic potentials (fEPSPs) after stimulation of the vagus. The proportion of neurons receiving vagal input was highest at the lesser curve (98%) and decreased gradually when recordings were made from neurons located toward the greater curve. Only a small proportion of neurons (4 of 85 cells) showed a slow EPSP after a burst of vagal stimulation. No postsynaptic inhibitory potentials were observed. There was no preferential vagal input to either gastric I, gastric II, or gastric III neurons. The fEPSPs were due to the release of acetylcholine acting postsynaptically on nicotinic receptors. The behavior of the fEPSPs suggests multiple vagal inputs to a majority of myenteric neurons. Our observations call into question the concept of enteric command neurons in favor of a divergent vagal input with widespread modulatory influences over gastric enteric neurotransmission.


1995 ◽  
Vol 353 (2) ◽  
pp. 161-178 ◽  
Author(s):  
Michael Schemann ◽  
Cornelia Schaaf ◽  
Michael Mäder

1994 ◽  
Vol 64 ◽  
pp. 90
Author(s):  
Shogo Matsuyama ◽  
Hideyo Sakjyama ◽  
Koji Nei ◽  
Shigenori Katayama ◽  
Norikazu Sakamoto ◽  
...  

1984 ◽  
Vol 66 (6) ◽  
pp. 701-708 ◽  
Author(s):  
B. C. Hurst ◽  
W. D. W. Rees ◽  
A. Garner

1. A DNA radioimmunoassay, sensitive in the range 25–1000 ng, has been developed to measure gastric mucosal cell loss. Validity of the assay was based on antibody specificity, absence of interference from gastric contents, parallel tracer displacement by dilutions of gastric and standard DNA, and crossover with colorimetric assay. 2. With this assay, gastric DNA shedding was examined in two animal species and man. In the guinea-pig stomach, DNA loss was 20–100 pg/h and in the canine Pavlov pouch, 260–580pg/h. In the canine Pavlov pouch stimulation of acid secretion by histamine and exposure to exogenous acid increased DNA output. In the normal human stomach DNA loss was 544 k 175 pg/h and in duodenal ulcer patients, 649 k 225 pg/li. 3. DNA radioimmunoassay provides a sensitive and reproducible measure of cell exfoliation from the stomach and may be a useful tool for studying aspects of gastric mucosal defence.


2003 ◽  
Vol 459 (1) ◽  
pp. 27-39 ◽  
Author(s):  
Sumei Liu ◽  
Hong-Zhen Hu ◽  
Chuanyun Gao ◽  
Na Gao ◽  
Guodu Wang ◽  
...  

1988 ◽  
Vol 22 (1-2) ◽  
pp. 156
Author(s):  
D. Renzi ◽  
P. Santicioli ◽  
C.A. Maggi ◽  
C. Surrenti ◽  
A. Calabrò ◽  
...  

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