296 VARIOUS EXPERIMENTAL GLYCOSURIAS 



pancreatic diabetes may be lowered by inducing renal 

 lesions. 68 In this stage of the poisoning, according to 

 L. Pollak, 69 it is possible to call out a glycosuria by super- 

 position of uranium poisoning, although the amount of sugar 

 in the blood is raised but little or not at all above the normal 

 by this measure. The explanation proposed is that while 

 cantharidin restricts the permeability of the vessels of the 

 kidneys for sugar, uranium makes them abnormally 

 permeable; and it is not improbable that a comparable 

 causative mechanism obtains in chromium and bichloride 

 of mercury glycosuria. A renal glycosuria has also been 

 observed occasionally in human beings with chronic 

 nephritis. 



The long list of glycosurias which are accompanied by 

 hyperglyccemia includes, according to L. Pollak (exclusive 

 of pancreatic diabetes which occupies a special position) a 

 number of glycosurias induced by sympathetic nervous irri- 

 tation. The factors producing the glycosuria are again to 

 be grouped in two classes: first, those which (analogous to 

 the sugar-puncture) occasion irritation of nervous centres 

 (transmitted by sympathetic fibres, especially the splanch- 

 nics, to the liver and cause the latter to throw off its glycogen 

 deposit) ; and second, those which (analogous to adrenin 

 glycosuria) cause an irritation of the peripheral endings of 

 the sympathetics. 



Sugar Puncture. We know enough about the essential 

 nature of the sugar puncture of Claude Bernard to under- 

 stand the parts the nerve impulses traverse which produce 

 glycosuria after injury of the floor of the fourth ventricle 

 of the brain. This nerve path extends from the " sugar 

 centre " to the cervical cord, thence out through communi- 

 cating branches to the lower cervical and upper thoracic 



08 A. Ellinger and A. Seelig (Konigsberg), Miinchener med. Wochenschr., 

 1905, 345, 449, and Festschr. f. M. Jaffe, p. 349, 1901. 



a9 L. Pollak (Pharmakol. Instit., Vienna), Arch. f. exper. Pathol., 64, 415, 

 1911. 



