750 FREDERICK S. HAMMETT 



of histamin with the uterine contracting principle on the fact that they 

 obtained /i relaxation of the rat or mouse uterus with histamin and a con- 

 traction with posterior lobe extracts, Abel and Macht (1919) showed that 

 this differential effect was probably due to the difference in the relative 

 strengths of the two solutions used, and that sufficiently dilute solutions 

 of histamin gave the same contracting reaction as did the posterior lobe 

 extracts, while concentrated doses of the latter exerted the same paralyzing 

 effect as did large amounts of histamin. In 1913-14 Guggenheim (&) (c) 

 had noted that there was a difference in stability of posterior lobe extracts 

 and histamin towards alkali. This was confirmed by Dudley (1919) 

 who extended the comparative study of these two preparations. He found 

 that histamin is not destroyed to any marked extent while posterior lobe 

 extracts lose their potency after a very short contact with sodium hydroxid. 

 Moreover, histamin is not destroyed by trypsin under the same conditions 

 that result in the destruction of the uterine-contracting principle of the 

 posterior lobe extracts. In addition histamin can be extracted from acid 

 solutions with butyl alcohol at low pressure only with great difficulty while 

 the active principle of the posterior lobe extracts is easily soluble in 

 this alcohol as it also is in chloroform, while histamin is not conspicu- 

 ously soluble in this latter reagent. The evidence thus far available speaks 

 against the idea that histamin is the active principle of the posterior 

 lobe concerned in its oxytocic activities. It has been suggested that the 

 presence of histamin in such extracts might be clue to a previous bac- 

 terial decomposition of the glandular substance before extraction. Hanke 

 and Koessler (1920) having devised a colorimetric method for the de- 

 termination of histamin in protein and protein-containing materials ana- 

 lyzed a lot of perfectly fresh beef pituitaries weighing three hundred 

 and forty-six grams and were unable to find histamin present. They, 

 therefore, conclude that perfectly fresh beef hypophysis does not con- 

 tain histamin," and suggested that the positive findings of Abel and 

 Kubota (1919) might well have resulted from the previous activity of 

 certain putrefactive microorganisms, which as is well known can and 

 do form histamin from histidin, a common constituent of animal proteins. 

 And I can say that from what I have seen of the condition of some of 

 the lots of pituitaries that have been used for the commercial preparation 

 of posterior lobe extracts that such a possibility is a probability if not a 

 certainty. In addition the studies of Jackson and Mills (1919) on the 

 comparative action of extracts of the hypophysis and histamin on the 

 bronchial musculature give further evidences of the physiological differ- 

 ence between the two active principles. Such a possibility is also to be 

 thought of in connection with the studies of Aldrich(c) (1915) on the pres- 

 ence of histidinrlike substances in posterior lobe extracts. 



Watanabe and Crawford (1916) were inclined to the opinion that 

 the active pressor principle of the posterior lobe is adrenin, but their 



