THE PHARMACOLOGICAL ACTION OF HARMALINE. 



247 



In 1901 Jacobson* showed that, in regard to their toxic effect on ciliated 

 epithelium, solutions of harmaline hydrochloride (among other fluorescent substances) 

 act independently of light in stronger concentrations, while in weaker concentrations 

 they are much more poisonous in light than in darkness. 



In August 1908 I obtained from Dr J. F. Thorpe, F.R.S., of Manchester University, 

 7 grammes of harmaline and 5 grammes of harmine for pharmacological investigation, 

 for which kindness I take this opportunity of expressing my great indebtedness to him. 



After performing a large number of experiments with harmaline, both with regard 

 to its general effects and its effects on isolated tissues, I have come to the conclusion 

 that the pharmacological actions of this alkaloid, almost without exception, resemble 

 intimately those of quinine ; and it is possible that this more extended investigation 

 may give, contrary to Tappeiner's conclusion, some pharmacological basis for the 

 therapeutic use of harmaline. Hence, in the course of the following account of the 

 pharmacology of harmaline, its various actions will be compared in detail with those of 

 quinine. 



A. Lethality of Harmaline. 



The lethality of harmaline was determined for frogs, guinea-pigs, rabbits, rats, and 

 cats, with the following results : — 



Table I. — Minimum Lethal Dose by Subcutaneous Injection for Frogs. 



No. of 



Weight of 



Dose per 



Actual Dose 







Experi- 



Frog 



Kilogramme 



in 



Result. 





ment. 



in Grammes. 



in Grammes. 



Grammes. 







1 



31 



0-05 



0-0015 



Recovery. 





2 



34 



01 



00034 







3 



20 



02 



0004 







4 



26 



02 



0-0052 







5 



38 



0-25 



0-0095 



Death in 31-36 hours. 





6 



32 



03 



0-0096 



„ before 20 l„ 





7 



28 



04 



0-011 



„ in 6 hours. 





8 



22 



045 



o-oi 







Table II. — Minimum Lethal Dose by Subcutaneous Injection for Guinea-pigs. 



No. of 

 Experi- 

 ment. 



9 



10 

 11 

 12 

 13 



Weight of 



Guinea pig 



in Grammes. 



500 

 450 

 470 

 500 

 500 



Does per 

 Kilogramme 

 in Grammes. 



001 

 004 

 08 

 0-1 

 0-2 



Actual Dose 



in 



Grammes. 



0-005 



0018 



0-038 



0-05 



01 



Result. 



Recovery — slight effects. 



,, marked effects. 



„ severe effects. 



Death in 7 hours 40 minutes. 



„ 33 minutes. 



Zeitschrift fur Biologic, Bd. xli., 1901, p. 445. 



