Yohimbine

Yohimbine is a potent and relatively nonselective alpha 2-adrenergicreceptor (AR) antagonist, with IC50 of 0.6 μM. IC50 value: 0.6 uM [1]Target: alpha 2-adrenergic receptorin vitro: Yohimbine inhibits alpha2-receptor antagonist with Ki of 1.05 nM, 1.19 nM, and 1.19 nM for α2A, α2B, α2C, respectively. Yohimbine also inhibits 5-HT1B with Ki of 19.9 nM. Yohimbine acts to block the lowering of cAMP by alpha-2 adrenoceptor agonists. yohimbine actually causes a pronounced lowering of tyrosinase activity. [3]in vivo: Yohimbine is an antagonist at alpha2-noradrenaline receptors with putative panicogenic effects in human subjects, was administered to Swiss-Webster mice at doses of 0.5, 1.0, and 2.0 mg/kg. Yohimbine potentiates active defensive responses to threatening stimuli in Swiss-Webster mice.[2]

Signaling Pathways >> GPCR/G Protein >> Adrenergic Receptor

Research Areas >> Neurological Disease

[1]. Saeed SA, et al. Signaling mechanisms mediated by G-protein coupled receptors in human platelets. Acta Pharmacol Sin. 2004 Jul;25(7):887-892.

[2]. Blanchard RJ, et al. Yohimbine potentiates active defensive responses to threatening stimuli in Swiss-Webster mice. Pharmacol Biochem Behav. 1993 Mar;44(3):673-681.

[3]. Fuller BB, et al. Downregulation of tyrosinase activity in human melanocyte cell cultures by yohimbine. J Invest Dermatol. 2000 Feb;114(2):268-276.

Isoprenaline hydrochloride | ICI 118,551 (hydrochloride) | Phenylephrine hydrochloride | Yohimbine hydrochloride | Adrenaline | Ivabradine hydrochloride | Prazosin hydrochloride | Clenbuterol hydrochloride | Phentolamine mesilate | guanfacine hydrochloride | pimozide | Sotalol hydrochloride | Carvedilol | Atenolol | Metroprolol succinate

DATA ITEMS CITED :

8

MOLECULAR FORMULA :

C21-H26-N2-O3

MOLECULAR WEIGHT :

354.49

WISWESSER LINE NOTATION :

T F6 D5 C666 EM ON&&TTTJ TQ UVO1

HEALTH HAZARD DATA

ACUTE TOXICITY DATA

TYPE OF TEST :

TDLo - Lowest published toxic dose

ROUTE OF EXPOSURE :

Oral

SPECIES OBSERVED :

Human - woman

DOSE/DURATION :

5 gm/kg

TOXIC EFFECTS :

Peripheral Nerve and Sensation - paresthesis Behavioral - ataxia Cardiac - change in rate

REFERENCE :

AEMED3 Annals of Emergency Medicine. (American College of Emergency Physicians, 1125 Executive Circle, Irving, TX 75038) Volume(issue)/page/year: 14,1002,1985

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Oral

SPECIES OBSERVED :

Rodent - mouse

DOSE/DURATION :

43 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

REFERENCE :

ARZNAD Arzneimittel-Forschung. Drug Research. (Editio Cantor Verlag, Postfach 1255, W-7960 Aulendorf, Fed. Rep. Ger.) V.1- 1951- Volume(issue)/page/year: 5,432,1955

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Intraperitoneal

SPECIES OBSERVED :

Rodent - mouse

DOSE/DURATION :

16 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

REFERENCE :

ARZNAD Arzneimittel-Forschung. Drug Research. (Editio Cantor Verlag, Postfach 1255, W-7960 Aulendorf, Fed. Rep. Ger.) V.1- 1951- Volume(issue)/page/year: 5,432,1955

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Subcutaneous

SPECIES OBSERVED :

Rodent - mouse

DOSE/DURATION :

37 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

REFERENCE :

ARZNAD Arzneimittel-Forschung. Drug Research. (Editio Cantor Verlag, Postfach 1255, W-7960 Aulendorf, Fed. Rep. Ger.) V.1- 1951- Volume(issue)/page/year: 5,432,1955

TYPE OF TEST :

LDLo - Lowest published lethal dose

ROUTE OF EXPOSURE :

Subcutaneous

SPECIES OBSERVED :

Rodent - rabbit

DOSE/DURATION :

50 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

REFERENCE :

HBAMAK "Abdernalden's Handbuch der Biologischen Arbeitsmethoden." (Leipzig, Ger. Dem. Rep.) Volume(issue)/page/year: 4,1418,1935

TYPE OF TEST :

LDLo - Lowest published lethal dose

ROUTE OF EXPOSURE :

Intravenous

SPECIES OBSERVED :

Rodent - rabbit

DOSE/DURATION :

11 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

REFERENCE :

HBAMAK "Abdernalden's Handbuch der Biologischen Arbeitsmethoden." (Leipzig, Ger. Dem. Rep.) Volume(issue)/page/year: 4,1418,1935 ** REPRODUCTIVE DATA **

TYPE OF TEST :

TDLo - Lowest published toxic dose

ROUTE OF EXPOSURE :

Intraperitoneal

DOSE :

1 mg/kg

SEX/DURATION :

male 1 day(s) pre-mating

TOXIC EFFECTS :

Reproductive - Paternal Effects - other effects on male

REFERENCE :

NLETDU Neuroendocrinology Letters. (Brain Research Promotion, D-7400, Tubingen, Germany) V.1- 1979- Volume(issue)/page/year: 12,69,1990 *** NIOSH STANDARDS DEVELOPMENT AND SURVEILLANCE DATA *** NIOSH OCCUPATIONAL EXPOSURE SURVEY DATA : NOHS - National Occupational Hazard Survey (1974) NOHS Hazard Code - 84715 No. of Facilities: 68 (estimated) No. of Industries: 1 No. of Occupations: 6 No. of Employees: 2770 (estimated)