PHYSIOLOGY OF ADIPOSE TISSUE 617 



the fat content of the denervated leg, as compared with the control leg, in 

 which the nerve supply was normal. Wertheimer 461 proved that section of 

 the spinal cord above the sixth thoracic segment prevented the develop- 

 ment of fatty livers in fasting phlorhizinized dogs, while scission below this 

 level did not prevent the fatty infiltration of this organ. On the other 

 hand, section of the nerves to the liver likewise failed to prevent the accu- 

 mulation of hepatic fat. The failure of fat mobilization after denervation 

 is also illustrated by the tests of Erben and Hasselbach 462 with phosphorus- 

 poisoned rats, and by those of Mill 463 with rats following hemorrhage. 

 These observations can be interpreted to mean that, in the absence of nerv- 

 ous irritation of the adipose tissue itself, fat mobilization, but not fat 

 deposition, is inhibited. 



Normal fat synthesis has been shown to take place following denervation 

 of adipose tissues. Thus, Hausberger 464 reported an influx of glycogen into 

 the denervated interscapular fat body of the mouse, while the symmetri- 

 cally located organ which possessed its normal innervation had a much lower 

 glycogen level. The accumulation of fat was likewise found to take place 

 more rapidly on the denervated side. 414 - 464 The denervated interscapulary 

 fat body in the mouse had a higher fat content under all conditions, in- 

 cluding fasting, than did the normally innervated control fat body. More- 

 over, it required long periods of time to deplete the denervated adipose 

 tissue of its fat reserves. 



There is some evidence that different nerves may exert their control either 

 on the mobilization or on the deposition phases of fat metabolism in adipose 

 tissue. Beznak and Hasch 465 found that the sympathetic nerves were in- 

 volved in both mobilization and deposition of fat in the perinephric adipose 

 tissue. According to Kure* and associates, 466 the sympathetic nerves in 

 dogs act as inhibitors of fat deposition, while stimulation of the parasympa- 

 thetic fibers brings about an acceleration of fat deposition. However, 

 following complete denervation, both phases of fat storage are reduced. 

 Such denervated tissues have a reduced metabolic rate. The deposition of 

 fat following injury to the hypothalamus is likewise believed to be of neuro- 

 genic origin. For a discussion of hypothalamic obesity, see page 625. 



Wertheimer and Shapiro 401 concluded that a normal innervation of adi- 



461 E. Wertheimer, Arch, exptl. Pathol. Pharmakol. (Naunyn-Schmiedeberg's), 160, 

 177-188(1931). 



462 F. Erben and H. Hasselbach, Z. ges. exptl. Med., 75, 145-166 (1931). 



463 E. Mill, Arch. ges. Physiol. (Pfluger's), 224, 304-314 (1930). 



464 F. X. Hausberger, Z. ges. exptl. Med., 102, 169-177 (1937). 



465 A. B. L. Beznak and Z. Hasch, Quart. J. Exptl. Physiol, 27, 1-15 (1937). 



466 K. Kure, T. Oi. and S. Okinaka, Klin. Wochschr., 16, 1789-1793 (1937). 



