312 DRUGS ACTING UPON THE GENITAL ORGANS 



Although a vast amount of study of the composition of ergot has 

 been made and it has been claimed on many occasions that the active 

 principles have been discovered, experience has shown that the sup- 

 posed active principle represented at most only a part of the activity 

 of the drug. 



It is certain, hovs^ever, that ergot contains several active prin- 

 ciples, some of them present in minute quantities but having ex- 

 traordinary activity, and there are at least four constituents which 

 should be mentioned. These are ergotoxine and ergotinine, two alka- 

 loids which are closely related, and two substances, tyramin and 

 histamin, commonly considered as putrefactive principles, because 

 they are present in putrefying meat. 



Ergotoxine, an extremely active alkaloid, is the hydrate of 

 ergotinine which is inactive but is probably changed into ergotoxine 

 under some conditions which are not understood. Ergotinine was 

 discovered many years ago but ergotoxine was only recently isolated 

 in pure form and represents the active portion of various substances 

 which have been isolated in different degrees of purity by different 

 investigators and given various names. 



Tyramin resembles epinephrine in its chemical composition and 

 physiological actions. It is formed from tyrosin during putrefac- 

 tion on account of which it received its name. It probably con- 

 stitutes the chief constituent of aqueous preparations of ergot, as 

 ergotoxine is insoluble in water. Tyramin causes active contractions 

 of the pregnant uterus. 



Histamin causes contraction of the uterus, constriction of some 

 vessels and dilatation of others, but is said to be present in ergot in 

 amounts too small to influence the uterine contraction of ergot to 

 any extent. According to some, however, its action is so vigorous 

 that it should not be ignored although it may escape isolation in 

 amounts that can be utilized profitably. It may be prepared syn- 

 thetically. Ergot also contains saponin which is of no importance 

 unless the drug is to be used intravenously. 



It is thought that all the pharmaceutical preparations which have 

 decided therapeutic activity contain either ergotoxine, tyramin or- 

 both. The following table will show the relationship between some 

 of the older preparations, and the active principles known to exist 

 as given by Barger and Dale : 



Ecbolin and Ergotin (Wenzell) : Mixture of alkaloids contain- 

 ing cholin (Meulenhoff). 



Sphacelinic acid (Koheri) : Inactive resin with adherent alka- 

 loid. 



Comutin (Koheri) : An alkaloidal resin probably containing 

 some ergotoxine, and also some other active substances which may be 

 a decomposition product of ergotoxine. 



