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FKANK A. HAKTMAN 



Epinephrin acts upon certain structures in the sympathetic ganglia 

 and the dorsal root ganglia (Hartman, Kilborn and Fraser(a) (&) ). This 

 has been shown by the direct application of epinephrin to the ganglia and 



Fig. 7. Dilatation of the hind limb of a dog (14 kgm.) due to 0.8 c.c. epinephrin, 

 1:50,000, twenty-two days after denervation. (Reduced one-half.) (After Hartman, 

 Kilborn and Fraser, Am. J. Physiol.) 



also by perfusion of the organ in question after cutting it off from the body 

 circulation, but avoiding injury to the nerve fibers, and then after severing 

 the central nervous connection with the ganglia, injecting epinephrin into 

 the circulation. When the sympathetic ganglia are being investigated 



Fig. 8. Dilatation of a perfused loop of intestine of a dog (weight 13.5 kgm.) 



caused by the injection of 2 c.c., 1:10,000 epinephrin into the jugular vein. Post- 



ganglionic fibers intact but all preganglionic fibers cut. (After Hartman, Kilborn and 

 Fraser, Am. J. Physiol.) 



the dorsal root ganglia are destroyed while if the latter are under in- 

 vestigation the former are destroyed. The usual gangiiar response is dila- 

 tation (Fig. 8) although occasionally constriction can be caused under 

 certain conditions (Hartman. Kilborn and Fraser (c), Fig. 9). 



