90 ALBERT C. CRAWFORD 



berg), gold (*hlorid (Gautier(&)), silver nitrate (Laignel-Lavastine(a)), 

 have been used for determining the presence and, in some cases, the amount 

 of Adrenalin. According to Borberg(a), oxidizing reagents respond to di- 

 lutions of 1-300,000, but beyond this the response is doubtful. 



Like other hydroxybenzenes, adrenalin gives a red color with a 

 solution of uranium nitrate and ammonia (Toujan(fr)). 



Quantitative Determination of Adrenalin 



Folin's reagent, which consists of a solution of 100 g. sodium tung- 

 state in 750 c.c water with the addition of 80 c.c. of an 85 per cent phos- 

 phoric acid solution, gives a blue color-reaction with adrenalin solutions 

 and responds to a dilution of 1 in 3,000,000 (Folin, Cannon and Denis). 



A very convenient method for determining the amount of adrenalin 

 in commercial solutions is by determining the amount of the pressor 

 activity of an unknown solution and comparing this rise with that 

 produced by a solution of a known strength (Houghton). Elliott (d) 

 claims that by this test, on decerebrate cats, he can determine the amount 

 of adrenalin present in solution to within 0.03 mgm., and perhaps within 

 0.01 mgm. The response of Folin's reagent is about that of the test made 

 by Elliott's method. 



Cameron has shown that the smallest amount of adrenalin which 

 will cause a definite and invariable rise in blood pressure in rabbits 

 weighing about 2,000 g. is 0.00062 nig. or 0.0003 per kilo. In cats, 

 Ehrmann found that the intravenous injection of 0.1 mg. caused a rise 

 which was just appreciable. Abel and Macht showed that in a dog 

 (6 kgm.) 0.000008 g. caused a rise of 26 mm. Hg. The blood pres- 

 sure method is not suited for determining the amount of adrenalin in 

 serum (Borberg). 



Strips of the cat's intestine are very sensitive to adrenalin. Magnus 

 showed that longitudinal strips of cat intestine are inhibited by adrenalin 

 even in dilutions 1 to 20,000,000 (Magnus). The intestinal method was 

 used by Cannon and his co-workers for the detection of minute amounts in 

 the blood. Later, Cannon used the denervated heart for this work. Intra- 

 venous injection of adrenalin, 0.001 mg. per kilo a minute, increased the 

 heart rate 28 beats per minute. 



Strips of rabbit intestine are as sensitive as those taken from the 

 cat (Hoskins). The intestinal strip method is more specific for adrenalin 

 than are the other biologic tests. At times, certain pituitary prepara- 

 tions relax intestinal strips (Bayer, and Peter). 



The frog eye test of Meltzer and Ehrmann does not yield results, 

 satisfactory for all cases of assay and frogs vary in their sensitiveness 

 (Borberg). Schultz finds it a reliable method of assay, but less delicate 



