106 Effects of Denervation 



The activity of the kallidin- (or bradykinin-) forming enzyme 

 kallikrein diminishes in the submaxillary gland and in saliva 

 secreted in response to adrenaline when the chorda has been cut 

 (Emmelin and Henriksson, 1953). With the atrophy of the submaxil- 

 lary gland caused by ligation of the duct a reduction in the content 

 of protease and amylase, of indophenol oxidase, succinic dehydro- 

 genase and acid phosphatase occurs (Junqueira, 1951). It- seems 

 particularly important to compare the activity of respiratory en- 

 zymes in normal and denervated glands in the light of the interest- 

 ing finding that secretion of saliva in a denervated gland occurs 

 with a smaller increase in oxygen consumption than in a normal 

 gland ; this has been shown both in vivo and in vitro, using chopped 

 salivary glands (Stromblad, 1957*2, 1959). Recently it has been 

 demonstrated that parasympathetic denervation reduces the activity 

 of succinic dehydrogenase, fumarase and cytochrome oxidase in 

 salivary glands (Nordenfelt, Ohlin and Stromblad, i960). This 

 fact may account for the decrease in maximal secretory capacity 

 which is seen after section of the chorda (Emmelin, Malm and 

 Stromblad, i960). Investigations on the composition of saliva 

 secreted by denervated glands in response to chemical stimuli 

 seem, also, highly desirable. 



The finding of Chang and Gaddum (1933) that the acetylcholine 

 content of the salivary glands decreases after parasympathetic 

 denervation has been discussed in a previous context. Similarly, 

 the content of adrenaline and noradrenaline has been found to 

 diminish on sympathetic denervation (v. Euler and Purkhold, 



CHANGES IN SENSITIVITY TO CHEMICAL STIMULI 



Denervation of the salivary glands causes a supersensitivity to 

 chemical agents, in agreement with Cannon's law of denervation. 

 It was shown by Maevsky (1923) and Fleming and Macintosh 

 (1935) that when the chorda had been cut in advance, the sub- 

 maxillary gland was more sensitive to adrenaline than normally. 

 Removal of the superior cervical ganglion was found by Simeone 

 and Maes (1939) to give rise to a supersensitivity in the gland. 

 Later investigators have mainly studied the submaxillary gland of 

 cats and dogs (Pierce and Gregersen, 1937; Wills, 1942; Emmelin 

 and Muren, 1950&, 195 \a, 1952; Graham and Stavraky, 1951, 

 1954; Emmelin, 1952a; Emmelin and Stromblad, 1953; Dim- 



