IT HAS LONG been known that the neuroeffector mechanism of denervated autonomic structures becomes sensitive to circulating hormones. This was stated by Cannon in 1939 as a law of denervation.1
When in a series of efferent neurons a unit is destroyed, an increased irritability to chemical agents develops in the isolated structure or structures, the effect being maximal in the part directly denervated.
This phenomenon of sensitization had been observed as far back as 1855, when Budge2 showed that the sympathetically denervated iris dilates in response to injections of epinephrine so small as to have no effect on the normal iris. Edes,3 in 1869, corroborated these findings and also showed that the vessels in the denervated ear of the rabbit became intensely constricted when the animal was excited. At that time the reason for this phenomenon was not understood.
In 1904, Meltzer and Auer4 studied the
JAFFE NS. PRACTICAL APPLICATION OF THE DENERVATED IRIS. Arch Ophthalmol. 1948;40(3):317-325. doi:10.1001/archopht.1948.00900030323010