Metabotropic glutamate receptors and nitric oxide in dopaminergic neurotoxicity

Table 1 Main findings on metabotropic glutamate receptors involvement in rotenone-induced neurotoxicity

Ref.	Object of study	mGluR type	Ligand
Luo et al[67], 2019	Cell culture; rats	mGluR5	Antagonist MPEP
Bai et al[66], 2018	Cell culture	mGluR5	Agonist CHPG; antagonist MPEP
Xia et al[65], 2015	Cell culture, rats	mGluR5	Antagonist MPEP
Bashkatova et al[69], 2012	Rats	mGluR5	Antagonist MPEP
Sun et al[64], 2012	Cell culture, rats	Group I mGluR	Agonist DHPG
Zhu et al[68], 2012	Cell culture, rats	mGluR5	Antagonist MPEP
Alam et al[70], 2009	Rats	mGluR5	Antagonist MPEP
Jiang et al[63], 2006	Cell culture	Group III mGluR	Agonist L-AP-4

mGluR: Metabotropic glutamate receptors; MPEP: 2-methyl-6-(phenylethynyl) pyridine; CHPG: (RS)-2-chloro-5-hydroxyphenylglycine; DHPG: (S)-3,5-dihydroxyphenylglycine.

Table 2 Main finding on the determination of nitric oxide and its products/metabolites in the rotenone model of neurotoxicity

Ref.	Dose of rotenone	Duration	NO or its products/metabolites	Method of NO determination
Kumar et al[91], 2021	2.0 mg/kg	28	Nitrite	Spectrophotometry
Parkhe et al[92], 2020	2.0 mg/kg	21	Nitrite	Spectrophotometry
Sharma et al[93], 2020	2.0 mg/kg	28	Nitrite	Spectrophotometry
Sun et al[80], 2019	1.5 mg/kg	28	Nitrate/nitrite	NO assay kit
Jayaraj et al[90], 2019	1.5 mg/kg	28	Nitrite	Spectrophotometry
Abdel-Salam et al[89], 2017	1.5 mg/kg × 3	7	Nitrite	Spectrophotometry
Javed et al[86], 2016	2.5 mg/kg	28	Nitrite	Spectrophotometry
Xiong et al[88], 2015	1.5 mg/kg	6	Nitrite	Spectrophotometry
Tapias et al[23], 2014	3.0 mg/kg	Individually1	3-NT (3-nitrotyrosine)	Immunofluorescence
Bashkatova et al[69], 2012	1.5 mg/kg	60	NO (Nitroxyl radical)	EPR
Bashkatova et al[78], 2004	1.5 mg/kg	60	NO (Nitroxyl radical)	EPR
He et al[76], 2003	2 mg/kg × 3	40	3-NT (3-nitrotyrosine)	HPLC

¹Tissue collection was carried out when each individual animal had reached endpoint (when the behavioral phenotype became debilitating, i.e., when akynesia, rigidity, and postural instability were manifested)[23]. NO: Nitric oxide; EPR: Electron paramagnetic resonance; HPLC: High performance liquid chromatography.