UNII:4956DJR58O

Mecamylamine hydrochloride is an orally active, nonselective, noncompetitive nAChR antagonist that can treat various neuropsychiatric disorders. Mecamylamine hydrochloride is originally used as a ganglionic blocker in treating hypertension. Mecamylamine hydrochloride can easily crosses the blood-brain barrier[1][2].

Signaling Pathways >> Membrane Transporter/Ion Channel >> nAChR

Signaling Pathways >> Neuronal Signaling >> nAChR

Research Areas >> Neurological Disease

nAChR[1]

Mecamylamine blocks muscle nAChRs in a use- and voltagedependent manner. Mecamylamine blocks the nicotinic currents via trapping mechanism. The main feature of this block is the phenomenon of block relief, which might be revealed by combined action of depolarization and activation of nAChRs. The experimental study of the Mecamylamine action on muscle nAChRs revealed that: (1) Mecamylamine (1-20 μM) reduces evoked end-plate currents (EPC) amplitude with Hill’s constant equal to 1.2 and IC50 = 7.8 μM at holding potential –70 mV; (2) the calculated depth of its interaction with the muscle nAChR channel is almost half of the one of neuronal nAChRs (0.37 compare to 0.72 for neuronal nAChRs); (3) simultaneous membrane depolarization and repetitive activation of postsynaptic nAChRs by motor nerve stimulation produced rapid block relief dependent on the degree of depolarization, number of conditioning signals and Mecamylamine concentration, and only slightly depended on the rate of stimulation[2].

Mecamylamine (0.5-1 mg/kg; Intraperitoneal injection; C57BL/6J mice) has antidepressant-like effects in both the TST and FST and these effects are dependent on bothβ2 andα7 subunits[3]. Animal Model: C57BL/6J mice (3-4 months) forced swim test (FST) and tail suspension test (TST)[3] Dosage: 0.5 mg/kg, 0.75 mg/kg, 1 mg/kg Administration: Intraperitoneal injection Result: Significantly decreased immobility time in the TST at the 1.0-mg/kg dose but did not alter baseline locomotor activity. Also significantly decreased time immobile in the FST.

[1]. Bacher I, et al. Mecamylamine - a nicotinic acetylcholine receptor antagonist with potential for the treatment of neuropsychiatric disorders. Expert Opin Pharmacother. 2009 Nov;10(16):2709-21.

[2]. Ostroumov K, et al. Modeling study of mecamylamine block of muscle type acetylcholine receptors. Eur Biophys J. 2008 Apr;37(4):393-402.

[3]. Rabenstein RL, et al. The nicotinic antagonist mecamylamine has antidepressant-like effects in wild-type but not beta2- or alpha7-nicotinic acetylcholine receptor subunit knockout mice. Psychopharmacology (Berl). 2006 Dec;189(3):395-401.

MOLECULAR FORMULA :

C11-H21-N.Cl-H

MOLECULAR WEIGHT :

203.79

WISWESSER LINE NOTATION :

L55 ATJ CM1 C1 D1 D1 &GH

HEALTH HAZARD DATA

ACUTE TOXICITY DATA

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Oral

SPECIES OBSERVED :

Rodent - rat

DOSE/DURATION :

208 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

REFERENCE :

JPETAB Journal of Pharmacology and Experimental Therapeutics. (Williams & Wilkins Co., 428 E. Preston St., Baltimore, MD 21202) V.1- 1909/10- Volume(issue)/page/year: 117,169,1956

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Intraperitoneal

SPECIES OBSERVED :

Rodent - rat

DOSE/DURATION :

53 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

REFERENCE :

RPOBAR Research Progress in Organic-Biological and Medicinal Chemistry. (New York, NY) V.1-3, 1964-72. Discontinued. Volume(issue)/page/year: 2,301,1970

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Subcutaneous

SPECIES OBSERVED :

Rodent - rat

DOSE/DURATION :

177 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

REFERENCE :

JPETAB Journal of Pharmacology and Experimental Therapeutics. (Williams & Wilkins Co., 428 E. Preston St., Baltimore, MD 21202) V.1- 1909/10- Volume(issue)/page/year: 117,169,1956

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Intravenous

SPECIES OBSERVED :

Rodent - rat

DOSE/DURATION :

21 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

REFERENCE :

RPOBAR Research Progress in Organic-Biological and Medicinal Chemistry. (New York, NY) V.1-3, 1964-72. Discontinued. Volume(issue)/page/year: 2,300,1970

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Oral

SPECIES OBSERVED :

Rodent - mouse

DOSE/DURATION :

92 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

REFERENCE :

NIIRDN Drugs in Japan (Ethical Drugs). (Yakugyo Jiho Co., Ltd., Tokyo, Japan) Volume(issue)/page/year: 6,814,1982

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Intraperitoneal

SPECIES OBSERVED :

Rodent - mouse

DOSE/DURATION :

17 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

REFERENCE :

RPOBAR Research Progress in Organic-Biological and Medicinal Chemistry. (New York, NY) V.1-3, 1964-72. Discontinued. Volume(issue)/page/year: 2,300,1970

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Subcutaneous

SPECIES OBSERVED :

Rodent - mouse

DOSE/DURATION :

81 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

REFERENCE :

RPOBAR Research Progress in Organic-Biological and Medicinal Chemistry. (New York, NY) V.1-3, 1964-72. Discontinued. Volume(issue)/page/year: 2,300,1970

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Intravenous

SPECIES OBSERVED :

Rodent - mouse

DOSE/DURATION :

14 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

REFERENCE :

RPOBAR Research Progress in Organic-Biological and Medicinal Chemistry. (New York, NY) V.1-3, 1964-72. Discontinued. Volume(issue)/page/year: 2,300,1970

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Oral

SPECIES OBSERVED :

Rodent - guinea pig

DOSE/DURATION :

175 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

REFERENCE :

JPETAB Journal of Pharmacology and Experimental Therapeutics. (Williams & Wilkins Co., 428 E. Preston St., Baltimore, MD 21202) V.1- 1909/10- Volume(issue)/page/year: 117,169,1956

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Intraperitoneal

SPECIES OBSERVED :

Rodent - guinea pig

DOSE/DURATION :

63 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

REFERENCE :

JPETAB Journal of Pharmacology and Experimental Therapeutics. (Williams & Wilkins Co., 428 E. Preston St., Baltimore, MD 21202) V.1- 1909/10- Volume(issue)/page/year: 117,169,1956

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Subcutaneous

SPECIES OBSERVED :

Rodent - guinea pig

DOSE/DURATION :

155 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

REFERENCE :

JPETAB Journal of Pharmacology and Experimental Therapeutics. (Williams & Wilkins Co., 428 E. Preston St., Baltimore, MD 21202) V.1- 1909/10- Volume(issue)/page/year: 117,169,1956 ** OTHER MULTIPLE DOSE TOXICITY DATA **

TYPE OF TEST :

TDLo - Lowest published toxic dose

ROUTE OF EXPOSURE :

Oral

SPECIES OBSERVED :

Mammal - dog

DOSE/DURATION :

1 gm/kg/8W-I

TOXIC EFFECTS :

Sense Organs and Special Senses (Eye) - mydriasis (pupillary dilation) Sense Organs and Special Senses (Eye) - lacrimation Nutritional and Gross Metabolic - weight loss or decreased weight gain

REFERENCE :

BJPCAL British Journal of Pharmacology and Chemotherapy. (London, UK) V.1-33, 1946-68. For publisher information, see BJPCBM. Volume(issue)/page/year: 13,501,1958