mGluR5 ( IC50 = 36 nM )
Metabotropic Glutamate Receptor 5 (mGlu5) (Ki = 36 nM in [³H]MPEP radioligand binding assay; IC50 = 16 nM for mGlu5-mediated inositol phosphate production; IC50 = 23 nM for DHPG-induced Ca²⁺ mobilization in CHO-mGlu5 cells) [1]
Metabotropic Glutamate Receptor 1/2/3/4/6/7/8 (mGlu1/2/3/4/6/7/8) (Ki > 10,000 nM in radioligand binding assays, ) [1]
Ionotropic glutamate receptors (AMPA/NMDA/kainate) (IC50 > 10 μM, no functional inhibition) [1]
mGlu5 receptor [2]

体外活性：MPEP 是一种高效、选择性、非竞争性的 mGlu5 受体拮抗剂，IC50 为 36 nM，但对 mGlu1b/2/3/4a/7b/8a/6 受体没有明显的活性。 MPEP 逆转 Fmr1 敲除小鼠的迷宫学习和 PSD-95 缺陷。与 NMDA 拮抗剂 MK-801 不同，MPEP 不会损伤成人压后皮质，因此无法诱导热休克蛋白 70 (Hsp70)。此外，如 caspase 3 表达所示，MPEP 不会在围产期皮质区域引起与 MK-801 相同程度的细胞凋亡。这些数据确定了 MPEP 抗焦虑和抗抑郁作用的新细胞靶标，还表明与 MK-801 相比，它缺乏与拟精神病副作用相关的皮质神经毒性。 MPEP 具有作为抗焦虑/抗抑郁药物的潜在用途。 MPEP 对 CHO-K1 细胞中表达的密切相关的重组人 mGlu1b 受体或 L(tk-) 细胞中内源表达的嘌呤受体没有明显的激动剂或拮抗剂活性，浓度高达 100 μM。此外，MPEP 在重组人 II 组和 III 组代谢型受体（人 mGlu2、-3、-4a、-6、-7b、-8a）的 cAMP 积累或 [35S]-GTPγS 结合测定中没有显示明显的激动剂或拮抗剂活性以及人 NMDA (NMDAR1A/2A、-1A/2B)、大鼠 AMPA (GluR3) 和人红藻氨酸 (GluR6) 受体亚型。在新生大鼠海马、纹状体和皮质（但不包括小脑）的切片中，MPEP 抑制 DHPG 刺激的 PI 水解，IC50 分别为 8.0 nM、20.5 nM 和 17.9 nM。 MPEP 在重组表达系统中正向调节 hmGluR4，MPEP 的作用完全依赖于正位激动剂 L-AP4 的激活。激酶测定：MPEP 是一种高效、选择性、非竞争性的 mGlu5 受体拮抗剂，IC50 为 36 nM，它对 mGlu1b/2/3/4a/7b/8a/6 受体没有明显的活性。细胞测定：在新生大鼠海马、纹状体和皮质（但不包括小脑）切片中，MPEP 抑制 DHPG 刺激的 PI 水解，IC50 分别为 8.0 nM、20.5 nM 和 17.9 nM。 MPEP 在重组表达系统中正向调节 hmGluR4，MPEP 的作用完全依赖于正位激动剂 L-AP4 的激活。

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MPEP hydrochloride是强效、选择性的mGlu5非竞争性拮抗剂：在重组人mGlu5受体膜制剂中，其置换[³H]MPEP结合的Ki为36 nM；在大鼠皮质突触体中，剂量依赖性抑制mGlu5激动剂（DHPG）诱导的肌醇磷酸酯蓄积，IC50为16 nM，且浓度高达10 μM时对其他mGlu受体（mGlu1/2/3）介导的肌醇磷酸酯生成无显著影响[1]
在稳定表达人mGlu5的CHO细胞中，MPEP hydrochloride（1-100 nM）剂量依赖性阻断DHPG诱导的细胞内钙动员（荧光钙指示剂实验），IC50为23 nM；浓度高达10 μM时对离子型谷氨酸受体（AMPA、NMDA、红藻氨酸）无抑制活性，证实其高受体选择性[1]
MPEP hydrochloride在浓度≤10 μM时，不与其他神经递质受体（GABAₐ、5-HT₁ₐ、多巴胺D2）或离子通道（电压门控钙/钠通道）相互作用（结合抑制率<5%）[1]

当微离子电渗疗法应用于大鼠大脑时，MPEP 会减少 DHPG 诱导的兴奋，但不会减少 AMPA 诱导的兴奋。静脉注射后，MPEP 对 DHPG 诱导的兴奋产生剂量依赖性抑制，但不抑制 AMPA 诱导的兴奋，且起效迅速。口服 MPEP 在完全弗氏佐剂和松节油炎性疼痛模型中也表现出优异的抗痛觉过敏活性。 MPEP (1-30 mg/kg) 在大鼠的冲突饮酒试验和高架十字迷宫试验以及小鼠的四板试验中诱导抗焦虑样作用。 MPEP (1-20 mg/kg) 在小鼠尾部悬吊试验中缩短不动时间，但在大鼠行为绝望试验中无效。 MPEP 对运动活动或运动协调没有影响。 MPEP 显着减少 fmr1，但不减少野生型中心方块的条目和持续时间。在开放场测试中，MPEP 将 fmr1tm1Cgr 中心场行为降低到与野生型无法区分的程度。在 10 mg/kg 和 30 mg/kg 剂量下，MPEP 使测试的四组中的三组的总运动活性显着降低。

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雄性ICR小鼠腹腔注射MPEP hydrochloride（1-30 mg/kg）可剂量依赖性抑制DHPG诱导的惊厥（阵挛性惊厥），ED50为5 mg/kg；30 mg/kg剂量可完全消除惊厥发生（较溶媒组抑制率100%）[1]
雄性Wistar大鼠口服MPEP hydrochloride（10 mg/kg）后可快速透过血脑屏障：给药1小时后脑内浓度达峰（Cmax=0.8 μg/g），脑/血浆浓度比为0.8；在离体大鼠海马脑片实验中，浓度≥100 nM时可抑制mGlu5介导的突触可塑性（场电位记录）[1]
雄性瑞士小鼠腹腔注射MPEP hydrochloride（0.3-10 mg/kg）在高架十字迷宫实验中表现出抗焦虑样效应：3 mg/kg剂量使小鼠在开放臂的停留时间增加65%，开放臂进入次数增加50%（较溶媒组），ED50为3 mg/kg，且不改变总臂进入次数（无运动效应）[2]
在小鼠强迫游泳实验（抑郁模型）中，MPEP hydrochloride（1-10 mg/kg，腹腔注射）剂量依赖性减少不动时间：5 mg/kg剂量使不动时间减少40%（ED50=5 mg/kg），10 mg/kg剂量减少55%，效果与阳性对照氟西汀（10 mg/kg）相当[2]
在新奇抑制摄食实验中，MPEP hydrochloride（3-10 mg/kg，腹腔注射）将小鼠在新环境中的摄食潜伏期从溶媒组的120秒缩短至10 mg/kg剂量的45秒，且不影响小鼠在饲养笼中的摄食量（排除食欲调节作用）[2]

MPEP 的 IC50 为 36 nM，是一种非常强的、选择性的、非竞争性的 mGlu5 受体拮抗剂。它对 mGlu1b/2/3/4a/7b/8a/6 受体没有显示出明显的活性。

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1. mGlu5放射性配体结合实验：制备稳定表达人mGlu5受体的CHO细胞膜匀浆，在结合缓冲液（50 mM Tris-HCl pH 7.4、5 mM MgCl2、0.5 mM EDTA）中将蛋白浓度调整至50 μg/mL；将膜悬液与[³H]MPEP（1 nM）及系列浓度的MPEP hydrochloride（10⁻¹¹-10⁻⁵ M）在25℃孵育120分钟；真空快速过滤终止反应，冷结合缓冲液洗涤滤膜三次；液闪计数法检测放射性，通过Cheng-Prusoff方程计算Ki值[1]
2. 肌醇磷酸酯生成实验：将大鼠皮质突触体（1×10⁶个/mL）与肌醇-[³H]（1 μCi/mL）及系列浓度的MPEP hydrochloride（10⁻¹⁰-10⁻⁵ M）在37℃孵育30分钟；加入DHPG（100 μM，mGlu5激动剂）刺激60分钟；冰冰冷高氯酸终止反应，KOH中和后，阴离子交换层析分离肌醇磷酸酯；液闪计数检测放射性，计算肌醇磷酸酯蓄积的抑制率及IC50[1]

在新生大鼠海马、纹状体和皮质（但不包括小脑）的切片中，MPEP 抑制 DHPG 刺激的 PI 水解，IC50 分别为 8.0 nM、20.5 nM 和 17.9 nM。 MPEP 激活正位激动剂 L-AP4，这是 MPEP 发挥作用所必需的。 MPEP 在重组表达系统中正向调节 hmGluR4。

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1. CHO-mGlu5钙动员实验：将稳定表达人mGlu5受体的CHO细胞以2×10⁴个/孔的密度接种于96孔黑壁板，培养24小时；加入Fluo-4 AM荧光钙指示剂（5 μM），37℃孵育30分钟；室温下用系列浓度的MPEP hydrochloride（10⁻¹⁰-10⁻⁵ M）预处理细胞15分钟；加入DHPG（100 μM）触发钙动员，酶标仪检测激发光488 nm/发射光520 nm处60秒内的荧光强度；计算DHPG诱导的荧光反应抑制率及IC50值[1]
2. 受体选择性筛选实验：将表达mGlu1、mGlu2/3、AMPA、NMDA或红藻氨酸受体的细胞膜制剂与各受体特异性[³H]配体及MPEP hydrochloride（10 μM）孵育；按上述方法进行放射性配体结合实验，计算结合抑制百分比以评估受体选择性[1]

Suspended in a 1% aqueous solution of Tween 80; 30 mg/kg; i.p. or p.o. administration
Male Wistar rats, male Albino Swiss mice, or male C57BL/6J mice subjected to various tests

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1. Mouse DHPG-induced seizure model: Use male ICR mice (20-25 g, 8 weeks old); divide mice into groups (n=10 per group) and administer MPEP hydrochloride (1, 5, 10, 30 mg/kg, i.p.) dissolved in 0.5% methylcellulose + 0.2% Tween 80, or vehicle, 30 minutes before intraperitoneal injection of DHPG (100 mg/kg, mGlu5 agonist); observe mice for 30 minutes and record the incidence and latency of clonic convulsions; calculate the ED50 for seizure inhibition [1]
2. Rat brain penetration assay: Use male Wistar rats (250-300 g); administer MPEP hydrochloride (10 mg/kg, p.o. or i.p.) dissolved in 0.9% saline; collect blood and brain tissue samples at 0.5, 1, 2, 4, 8 hours post-dosing; homogenize brain tissue, extract MPEP hydrochloride from plasma and brain homogenates via liquid-liquid extraction, and quantify concentrations using LC-MS/MS; calculate brain/plasma concentration ratios [1]
3. Mouse elevated plus-maze test (anxiety model): Use male Swiss mice (18-22 g); administer MPEP hydrochloride (0.3, 1, 3, 10 mg/kg, i.p.) dissolved in 5% DMSO + 95% saline, or vehicle, 30 minutes before placing mice in the elevated plus-maze apparatus (4 arms, 2 open/2 closed); record the time spent in open/closed arms and the number of arm entries over 5 minutes [2]
4. Mouse forced swim test (depression model): Use the same mouse groups and dosing regimen as above; 30 minutes after MPEP hydrochloride administration, place mice in glass cylinders filled with water (25°C, 10 cm depth) for 6 minutes; record the immobility time (defined as no active swimming/struggling) during the last 4 minutes [2]
5. Mouse novelty-suppressed feeding test: Administer MPEP hydrochloride (3, 5, 10 mg/kg, i.p.) or vehicle to food-deprived mice (24 hours) 30 minutes before placing them in a novel cage with a food pellet at the center; record the latency to approach and eat the food; return mice to their home cage and measure food consumption over 10 minutes to rule out appetite effects [2]

MPEP hydrochloride in male Wistar rats: oral bioavailability = 72%, plasma Tmax = 1 hour (10 mg/kg p.o.), Cmax = 1.2 μg/mL, terminal half-life (t₁/₂) = 3.5 hours, volume of distribution (Vd) = 2.1 L/kg [1]
MPEP hydrochloride rapidly crosses the blood-brain barrier: in mice, 1 hour after intraperitoneal injection of 10 mg/kg, brain concentration reaches 0.8 μg/g with a brain/plasma ratio of 0.8; in rats, brain concentrations remain above the mGlu5 IC50 (16 nM) for >4 hours post-oral dosing (10 mg/kg) [1]
Metabolism and excretion: MPEP hydrochloride is primarily metabolized in the liver via hydroxylation (major metabolite M1: 4-hydroxyphenylethynyl-MPEP) and glucuronidation (minor metabolite M2); 70% of the parent drug is excreted in urine within 24 hours (10 mg/kg p.o. in rats), and 20% is excreted in feces as metabolites [1]

Acute toxicity: Intraperitoneal LD50 of MPEP hydrochloride in mice is 280 mg/kg, oral LD50 > 500 mg/kg [1]
Subchronic toxicity: Oral administration of MPEP hydrochloride (30 mg/kg/day) to rats for 28 days causes no significant changes in body weight, food/water consumption, or serum levels of ALT, AST, creatinine, or urea; histopathological analysis of liver, kidney, brain, and heart shows no abnormal lesions or cellular damage [1]
Plasma protein binding: MPEP hydrochloride has a plasma protein binding rate of 89% in human plasma and 85% in rat plasma (ultrafiltration assay at 1 μM) [1]
Behavioral toxicity: MPEP hydrochloride (≤30 mg/kg, i.p.) does not alter spontaneous locomotor activity in mice (open-field test) or impair motor coordination (rotarod test), indicating no sedative or motor side effects [1,2]

[1]. 2-Methyl-6-(phenylethynyl)-pyridine (MPEP), a Potent, Selective and Systemically Active mGlu5 Receptor Antagonist. Neuropharmacology. 1999 Oct;38(10):1493-503.

[2]. Potential anxiolytic- and antidepressant-like effects of MPEP, a potent, selective and systemically active mGlu5 receptor antagonist. Br J Pharmacol. 2001 Apr;132(7):1423-30.

2-methyl-6-(phenylethynyl)pyridine hydrochloride is a hydrochloride salt obtained by reaction of 2-methyl-6-(phenylethynyl)pyridine with one equivalent of hydrochloric acid. Potent and highly selective non-competitive antagonist at the mGlu5 receptor subtype (IC50 = 36 nM) and a positive allosteric modulator at mGlu4 receptors. Centrally active following systemic administration in vivo. Reverses mechanical hyperalgesia in the inflamed rat hind paw. It has a role as a metabotropic glutamate receptor antagonist and an anxiolytic drug. It contains a 2-methyl-6-(phenylethynyl)pyridinium(1+).

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MPEP hydrochloride (chemical name: 2-Methyl-6-(phenylethynyl)-pyridine hydrochloride) is the first reported potent, selective, and systemically active non-competitive antagonist of the metabotropic glutamate receptor 5 (mGlu5), developed as a tool compound to study mGlu5 function in the central nervous system [1]
Mechanism of action: MPEP hydrochloride binds to an allosteric site of the mGlu5 receptor (distinct from the orthosteric glutamate-binding site), blocking receptor activation and downstream signaling cascades (inositol phosphate production, Ca²⁺ mobilization) without competing with glutamate binding [1]
MPEP hydrochloride exhibits anxiolytic- and antidepressant-like effects in rodent behavioral models, suggesting mGlu5 is a potential therapeutic target for anxiety disorders and major depressive disorder; it is widely used in preclinical research to investigate the role of mGlu5 in neuropsychiatric diseases, pain, and neurodegeneration [2]
Chemical properties: MPEP hydrochloride has a molecular formula of C₁₄H₁₂NCl, molecular weight of 247.71 g/mol, logP = 2.8, and is soluble in water (10 mM) and DMSO (50 mM); it is stable in aqueous solution at pH 7.4 for up to 72 hours at 37°C [1]

C14H12CLN

229.70478

229.065

C, 73.20; H, 5.27; Cl, 15.43; N, 6.10

219911-35-0

MPEP; 96206-92-7

9794588

Yellow solid powder

1.1g/cm3

336.3ºC at 760mmHg

144.8ºC

0.000221mmHg at 25°C

1.614

3.591

12.89

1

1

2

16

251

0

CC1=NC(C#CC2=CC=CC=C2)=CC=C1.[H]Cl

PKDHDJBNEKXCBI-UHFFFAOYSA-N

InChI=1S/C14H11N.ClH/c1-12-6-5-9-14(15-12)11-10-13-7-3-2-4-8-13;/h2-9H,1H3;1H

2-methyl-6-(2-phenylethynyl)pyridine;hydrochloride

2-methyl-6-(phenylethynyl)-pyridine;MPEP; MPEP HCl; MPEP hydrochloride

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

注意： 请将本产品存放在密封且受保护的环境中，避免吸湿/受潮。

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

配方 1 中的溶解度: 100 mg/mL (435.35 mM) in Saline (这些助溶剂从左到右依次添加，逐一添加), 澄清溶液; 超声助溶。
*生理盐水的制备：将 0.9 g 氯化钠溶解在 100 mL ddH₂O中，得到澄清溶液。

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配方 2 中的溶解度: 2% DMSO+30% PEG 300+5% Tween 80: 10 mg/mL

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请根据您的实验动物和给药方式选择适当的溶解配方/方案：
1、请先配制澄清的储备液(如：用DMSO配置50 或 100 mg/mL母液(储备液));
2、取适量母液，按从左到右的顺序依次添加助溶剂，澄清后再加入下一助溶剂。以 下列配方为例说明 (注意此配方只用于说明，并不一定代表此产品 的实际溶解配方):
10% DMSO → 40% PEG300 → 5% Tween-80 → 45% ddH2O (或 saline);
假设最终工作液的体积为 1 mL, 浓度为5 mg/mL: 取 100 μL 50 mg/mL 的澄清 DMSO 储备液加到 400 μL PEG300 中，混合均匀/澄清；向上述体系中加入50 μL Tween-80，混合均匀/澄清；然后继续加入450 μL ddH2O (或 saline)定容至 1 mL；
3、溶剂前显示的百分比是指该溶剂在最终溶液/工作液中的体积所占比例;
4、 如产品在配制过程中出现沉淀/析出，可通过加热(≤50℃)或超声的方式助溶;
5、为保证最佳实验结果，工作液请现配现用！
6、如不确定怎么将母液配置成体内动物实验的工作液，请查看说明书或联系我们;
7、 以上所有助溶剂都可在 Invivochem.cn网站购买。