ADRENALINE (EPINEPHRIN, ADRENINE) 103 



use of serum. According to Stewart it is possible to prove the pres- 

 ence of adrenaline only in the blood from the supra-renal vein. 



Besides those on the circulatory system, the other effects of adrena- 

 line on plain muscle, described in a previous section, are to some 

 extent available for the quantitative estimation of the drug ; the 

 methods which have been suggested, based on these effects, are much 

 less accurate than the blood-pressure method, but, on the other hand, 

 some of them are more suitable for the very rough estimation of 

 extremely minute quantities of adrenaline, such as may occur in the 

 blood or in tissue extracts. In such cases it is, however, necessary to 

 avoid confusion with other ill-defined substances (such as vaso-dilatin, 

 p. 30) which may produce similar effects in plain muscle (cf. Hoskins 

 [191 1] and O'Connor [1912, i]). 



O. B. Meyer [1906] has employed isolated rings of the sub- 

 clavian or carotid artery of the ox, which contract in solutions of 

 adrenaline up to I : 1,000,000,000 (0-000015 mg. in 15 c.c. Ringer's 

 solution). Cow [1911] has investigated other arteries by this 

 method and finds that the only arteries not constricted by adrenaline 

 are the intravisceral portion of the pulmonary, the coronary and the 

 cerebral arteries. Argyll Campbell [1911] also finds by this method 

 that adrenaline causes marked constriction of the vessels of all 

 organs, except those of the heart and lungs. A slight constriction 

 occurs occasionally in the heart and more frequently in the lung 

 vessels. 



A. Frankel [1909] used the isolated uterus of the rabbit, which 

 still reacts to adrenaline at a dilution of I : 20,000,000, but Hoskins 

 [1911] states that this reaction is not specific and that contractions 

 are caused by a large nunober of glandular and tissue extracts ; the 

 use of the rabbit's uterus for testing serum has also been criticised by 

 Stewart [1912]. 



Cannon and de la Paz [1911] employed longitudinal strips of muscle 

 from the rabbit's intestine and Hoskins [191 1] a short length of small 

 intestine from the same animal. These two methods depend on the 

 inhibition, by adrenaline, of the spontaneous contractions. In Hoskins's 

 experiments this inhibition occurred regularly at I : 100,000,000 and 

 sometimes even at I : 500,000,000. Hoskins considers his method 

 and that of O. B. Meyer (above) to be the most sensitive methods 

 known. According to O'Connor [1912, l] substances are formed 

 during the coagulation of blood with actions simulating this and other 

 effects of adrenaline, but by using the plasma, instead of the serum, 

 and rabbit's intestine as test object, he finds that the blood from the 



