458 



METABOLISM, NUTRITION, AND DIET 



the medulla. The contraction of the skeletal muscles in response to a single 

 stimulation is increased. 



Very small doses of suprarenal extract are sufficient to produce marked 

 effects. Thus Schafer states that less than ^T^O" gram ( ^ grain) of the 

 desiccated gland is sufficient to produce an effect upon the heart and arteries 

 of an adult man. 



It is a curious fact that only extracts of the medullary portion of the gland 

 are active. It has been further shown, by Christian! and others, that if only 



FIG. 313. Injection of Suprarenal Extract. Effect upon the heart, limb, spleen and 

 blood pressure, after section of cord and vagi. (Reduced to one-half.) (Schafer.) 



small portions of the medulla remain, the animal operated upon survives; 

 while if all the medullary substance be removed, even though large portions 

 of the cortex remain, the animal invariably dies. 



Abel has succeeded in separating the blood-pressure-raising constituent 

 of the gland extract, and calls it epinephrin, C 10 H 13 NO 3 JH 2 O. Takamine 

 isolated an active principle to which he assigned the formula C 9 H 13 NO 3 , 

 and the name adrenalin. The hydrochloride salt is prepared commercially 

 and produces all the vascular effects assigned to the gland. 



Destruction of the suprarenal capsules through disease in man results in 

 the production of a group of symptoms known as Addison's disease. The 



