Localization and role of metabotropic glutamate receptors subtype 5 in the gastrointestinal tract

Table 1 Literature assessing metabotropic glutamate 5 receptor localization in the gastrointestinal tract and accessory digestive organs

Organs	Role/disorder	Animal/human study	Measurement/observation	Ref.
Mouth	Mechanical allodynia	Rats	Antagonists block allodynia	[11-13]
Mouth	Inflammation/pain	Rats	Upregulation of receptor expression	[10]
Mouth	Inflammation	Human pulp	Receptor-mediated inflammatory nociception.	[14]
Mouth	Oral cancer	Human tissue	Tumor progression, cell migration	[16]
Esophagus/stomach	TLESR (transient lower sphincter relaxation)	Ferrets	Reduction in reflux	[17,20]
Esophagus/stomach	TLESR	Humans	Reduction in reflux	[22-24]
Esophagus/stomach	TLESR	Humans	Reduction in reflux	[25]
Intestine	Intestinal inflammation	Pigs and mice	Decreased mGluR5 expression	[30]
Intestine	Visceral pain	Rats and mice	mGluR5 antagonists inhibit colorectal distension-evoked visceromotor (VMR)	[31]
Intestine	Epithelial barrier function	Mice	mGluR5 antagonists improve the epithelial barrier function	[32]
Tongue	Inflammation	Rats	Mechanical and heat hypersensitivity	[33]
Tongue	Cancer	Human cell lines	Antagonists block tumor cell migration and invasion	[16]
Tongue	Cancer	Mice	Antagonists block tumor cell migration	[34]
Liver	Hypoxia	Rats and mice	Necrosis, reactive oxygen species (ROS)	[36,37]
Liver	Acetaminophen damage	Mice	ROS iNOS	[42]
Liver	Cancer	Mice	Tumor reduction	[47]
Liver	Fulminant hepatitis	Mice	Mortality, Lipid peroxidation	[44]
Liver	Mitochondrial damage	Rats	Mitochondrial membrane potential	[46]
			ROS production
Pancreas	Insulin release	Rats	Change in glucose concentration	[48]
Pancreas	Insulin secretion	Rats and mice	Glucose-stimulated intracellular Ca2+	[5]