Effect of L‐glutamic acid on acid secretion and immunohistochemical localization of glutamatergic neurons in the rat stomach

Tsai, Li Hsueh; Tsai, Wen-Hsuan; Wu, Jang‐Yen

doi:10.1002/jnr.490380209

Cited by 36 publications

(48 citation statements)

References 17 publications

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“…Nicotinic cholinergic neurons have also been suggested to play a role in regulating the secretion of gastric acid [23]. Our recent investigation has confirmed that L-Glu reduces the oxotremorine-, histamine-, or gastrinstimulated gastric acid secretion, perhaps through its interaction with the non-NMDA ionotropic EAA receptors [28].…”

Section: Introductionsupporting

confidence: 54%

“…The immunohistochemical procedure was similar to that described elsewhere [28]. Briefly, male Sprague-Dawley rats were initially anesthetized by an intraperitoneal injection of sodium pentobarbital (50 mg/kg), followed by perfusion with 1 liter saline at 37°C, and subsequent fixation with 4% paraformaldehyde in phosphatebuffered saline (PBS) (50 mM potassium phosphate buffer, pH 7.4, containing 0.9% NaCl) at 4°C.…”

Section: Immunohistochemical Proceduresmentioning

confidence: 99%

“…Experiments on the everted whole stomach were performed as described elsewhere [28]. Briefly, male Sprague-Dawley rats (weight 180-250 g) were deprived of food overnight, but allowed free access to water to ensure that the stomach was free of solid contents.…”

Section: Experiments On the Everted Whole Stomachmentioning

confidence: 99%

“…The rats were decapitated and the stomach was removed immediately for use. The isolated everted whole stomach was prepared as described elsewhere [27,28], with only slight modifications. The entire everted organ was then placed in a 20-ml organ bath containing the mucosal saline solution (in mM ; NaCl, 119; KCl, 4.7; CaCl 2 , 2.5; glucose, 5.6; pH 5.2) at 30 B 1°C and continuously bubbled with 100% O 2 .…”

Section: Experiments On the Everted Whole Stomachmentioning

confidence: 99%

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Effect of Excitatory Amino Acid Neurotransmitters on Acid Secretion in the Rat Stomach

Tsai

Lee

1999

J Biomed Sci

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Excitatory amino acids (EAAs), in particular, L-aspartate (L-Asp) neurons and their processes, were localized in the rat stomach using a immunohistochemical method with specific antibodies against either L-Asp or its synthesizing enzyme, aspartate aminotransferase (AAT). Myenteric ganglia and nerve bundles in the circular muscle and in the longitudinal muscle were found to be AAT- or L-Asp-positive. In addition, AAT- or L-Asp-positive cells were also found in the muscle layer and the deep mucosal layer. The distribution of AAT- or L-Asp-positive cells in both the mucosal and muscle layers was heterogeneous in the stomach. In addition, L-Asp at 10^–6 M negligibly influenced acid secretion in an everted preparation of isolated rat stomach. However, according to our results, L-Asp markedly inhibited the histamine-stimulated acid secretion, but not the oxotremorine- or the pentagastrin-stimulated acid secretion. Furthermore, L-Asp also inhibited histamine-induced elevation of cAMP. L- Asp itself did not affect the cAMP level although it elevated the cGMP level in the stomach. Moreover, either (+)2-amino-5-phosphonovaleric acid or (±)3-(2-carboxypiperazin-4-yl)prophyl-1-phosphonic acid, i.e. two specific antagonists for N-methyl-D-aspartic acid (NMDA) receptors, blocked the inhibitory effect of L-Asp on histamine-stimulated acid secretion or histamine-induced elevation of cAMP. Since cAMP has been strongly implicated as the second messenger involved in histamine-induced acid secretion, we believe that L-Asp regulates acid secretion in the stomach by inhibiting histamine release through the NMDA receptors, subsequently lowering the level of cAMP and ultimately reducing acid secretion.

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Section: Introductionsupporting

confidence: 54%

Section: Immunohistochemical Proceduresmentioning

confidence: 99%

Section: Experiments On the Everted Whole Stomachmentioning

confidence: 99%

Section: Experiments On the Everted Whole Stomachmentioning

confidence: 99%

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Effect of Excitatory Amino Acid Neurotransmitters on Acid Secretion in the Rat Stomach

Tsai

Lee

1999

J Biomed Sci

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“…In the CNS, electrophysiological L-Glu and L-Asp are less potent than NMDA due to their avid uptake by the tissue 102 , but there appears to be an absence of the uptake processes of these compounds in the myenteric plexus 95,96 . However, Glu and Asp are both involved in regulating acid secretion in the stomach, but the mode of action of each is different 652,658 . Asp was more specific than Glu in regulating acid secretion.…”

Section: Gastrointestinal Tractmentioning

confidence: 99%

A Review of Glutamate Receptors II: Pathophysiology and Pathology

Rousseaux

2008

J Toxicol Pathol

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Seventy years ago it was discovered that glutamate plays a central role in brain metabolism and is abundant in the brain. Glutamate was then found to be the principal excitatory neurotransmitter in the brain. As stated in the first article of this series, there are three families of ionotropic receptors with intrinsic cation permeable channels: Nmethyl-D-aspartate [NMDA], α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid [AMPA] and kainate [Ka].Among these there are three groups of metabotropic, G protein-coupled glutamate receptors [mGluR] that modify neuronal and glial excitability through G protein subunits acting on membrane ion channels and second messengers such as diacylglycerol and cAMP. There are also two glial glutamate transporters and three neuronal transporters in the brain. Although glutamate is the most abundant amino acid in the diet, there is no evidence for brain damage in humans resulting from dietary glutamate. However, a Ka analog, domoate, is sometimes ingested accidentally in blue mussels; this potent toxin causes limbic seizures, which can lead to hippocampal and related pathology and amnesia. Endogenous glutamate may contribute to the brain damage occurring acutely after status epilepticus, cerebral ischemia or traumatic brain injury by activating NMDA, AMPA or mGluR 1 receptors. Glutamate may also contribute to chronic neurodegeneration in such disorders as amyotrophic lateral sclerosis and Huntington's disease. In animal models of cerebral ischemia and traumatic brain injury, NMDA and AMPA receptor antagonists protect against acute brain damage and delayed behavioral deficits. Other clinical conditions that may respond to drugs acting on glutamatergic transmission include epilepsy, amnesia, anxiety, hyperalgesia and psychosis. In this second part of this review, we will explore those diseases in which the pathophysiology and pathology are associated, in part, with the glutamate system. (J Toxicol Pathol 2008; 21: 133-173)

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Innervation of the gastric mucosa

Ekblad

Mei

Sundler

2000

Microsc. Res. Tech.

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A plethora of neuronal messengers (“classical” transmitters, gaseous messengers, amino acid transmitters, and neuropeptides) are capable of mediating or modulating gastric functions. Accordingly, the stomach is richly innervated. Gastric nerves are either intrinsic to the gastric wall, i.e., they have their cell bodies in the intramural ganglia and thus belong to the enteric nervous system, or they reach the stomach from outside, originating in the brainstem, in sympathetic ganglia, or in sensory ganglia. Topographically, the nerve fibers in the stomach reach all layers from the most superficial portions of the gastric glands to the outer smooth muscle layer. This wide distribution implies that virtually all different cell types may be reached by neuronal messengers. Within the gastric mucosa endocrine and paracrine cells (e.g., gastrin cells, ECL cells, somatostatin cells), exocrine cells (parietal cells, chief cells, mucous cells), smooth muscle cells, and stromal cells are regulated by neuronal messengers. The sensory innervation, responding to capsaicin, plays an important role in mucosal protection, and in ulcer healing. Presumably also other nerves are involved and a plasticity in the neuropeptide expression has been demonstrated at the margin of gastric ulcers. Taken together, available data indicate a complex interplay between hormones, paracrine messengers and neuronal messengers, growth factors and cytokines in the regulation of gastric mucosal activities such as secretion, local blood flow, growth, and restitution after damage. Microsc. Res. Tech. 48:241–257, 2000 © 2000 Wiley‐Liss, Inc.

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Effect of L‐glutamic acid on acid secretion and immunohistochemical localization of glutamatergic neurons in the rat stomach

Cited by 36 publications

References 17 publications

Effect of Excitatory Amino Acid Neurotransmitters on Acid Secretion in the Rat Stomach

Effect of Excitatory Amino Acid Neurotransmitters on Acid Secretion in the Rat Stomach

A Review of Glutamate Receptors II: Pathophysiology and Pathology

Innervation of the gastric mucosa

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