Parasympathetic Secretory Innervation 45 



a dog, the other in a cat. The figure shows in addition that some 

 acetylcholine appears in the effluent when the nerve is not stimu- 

 lated; this is the case even in the presence of the curarine. Since 

 this seemed to be the first demonstration of a release of acetyl- 

 choline in a parasympathetic ganglion, attempts were made to find 

 further arguments supporting the view that the preganglionic 

 chorda fibres are cholinergic. The nerves were found to contain 

 acetylcholine in fairly high concentration. Further, it is known 



Acetylcholine 0-32-, 



Control 

 sample 



Stimul. 

 sample 



Esermized 

 plasma 



Eserme- 

 curare pi. 



Esermized 

 plasma 



E serine - 

 curare pi. 



Fig. 3.2. Output of acetylcholine from the submaxillary gland of a dog 



and a cat. 



The glands were perfused with heparinized plasma containing eserine io -5 and in the second 

 part of the experiment in addition curarine io~ 4 . Each column represents the acetylcholine con- 

 tent in a sample of perfusate collected during 3 minutes. Stimulation samples were collected when 

 the chorda had been excited during the first 2 minutes of the period with 20 supramaximal shocks 

 per sec. Assay of acetylcholine on blood pressure of eviscerated, eserinized cat (Emmelin and 

 Muren, 1950). 



from cross-suture experiments that functional union can be estab- 

 lished between the peripheral stump of the transected chorda and 

 the central end of some other efferent nerve, containing cholinergic 

 fibres, for instance the hypoglossal nerve (see Emmelin, Muren 

 and Stromblad, 19570). Since it is generally assumed that cholin- 

 ergic fibres of one nerve can functionally replace fibres of another 

 nerve only if these are cholinergic too (Dale, 1934), further support 

 is thus given to the view that acetylcholine acts as mediator across 

 the parasympathetic ganglion of the submaxillary gland. A clinical 

 counterpart to the cross-suture experiments may also be quoted. 



