LIPID STORAGE UNDER ABNORMAL CONDITIONS 625 



the blood sugar level exert a pronounced effect upon the appetite. There is 

 also some evidence that the hypothalamus is sensitive to changes in the 

 blood sugar level. 503 The repeated stimulation of insulin production may 

 develop into a vicious cycle, which becomes difficult to counteract. The 

 success of the treatment of obesity by the use of a protein-fat diet, as em- 

 ployed by Pennington, 504 may be attributable not only to a reduced food 

 consumption due to the satiety value of the high-fat diet, but also to the 

 absence of a continued stimulation of the appetite, as a result of hypogly- 

 cemia produced by diets containing large proportions of carbohydrate. 

 Ingle 505 reported that marked obesity can be produced in rats by the simple 

 expedient of force-feeding. 



(a) Obesity Due to Hyperinsulinism. MacKay and associates 506 - 507 dem- 

 onstrated that rats grew excessively fat when protamine insulin was in- 

 jected frequently, and they were given a high-starch diet ad libitum. 

 Ordinary insulin did not influence either the food intake or the body weight. 



Peters 508 cited a similar type of obesity, in human patients, which may 

 occur spontaneously. Thus, an uncontrollable hunger has been noted in 

 patients who have a spontaneous hypoglycemia, sometimes but not always 

 referable to a tumor in the islands of Langerhans. It is suggested that the 

 overeating which provokes the obesity is a self-protective response. 



(b) Obesity Due to Lesions of the Hypothalamus. It has long been rec- 

 ognized that, when injury of the hypothalamus results from tumors or 

 from related destructive lesions in this area of the brain, obesity is the 

 logical consequence. As early as 1840, Mohr 509 reported a typical case of 

 obesity suddenly occurring in a 57-year-old woman who had suffered from 

 "mental deterioration" for the preceding three years. Following her sud- 

 den death, which occurred not long after the development of the obesity, 

 a large pituitary tumor was demonstrated which had presumably affected 

 the area of the hypothalamus. 



The area of the brain injury which will cause obesity has been a matter of 

 controversy over a number of years. Although the original case of adiposa 

 genitalis described by Frohlich 510 in 1901 involved a hypothalamic tumor, 



803 J. Mayer, J. J. Vitale, and M. W. Bates, Nature, 167, 562-563 (1951). 



604 A. W. Pennington, Ind. Med. and Surg., 20, 267-271 (1951). 



605 D. J. Ingle, Endocrinologij, 39, 43-51 (1946). 



506 E. M. MacKay, J. W. Callaway, and R. H. Barnes, /. Nutrition, 20, 59-66 (1940). 



607 E. M. MacKay and J. W. Callaway, Proc. Soc. Exptl. Biol. Med., 86, 406-407 (1937). 



608 J. P. Peters and associates, unpublished observations; cited by J. P. Peters and 

 D. D. Van Slyke, Quantitative Clinical Chemistry, 2nd ed., Vol. I, Williams & Wilkins, 

 Baltimore, 1946, p. 42. 



509 Mohr, Wochschr. ges. Heilk,, 1840, No. 35, 565-571. 



510 A. Frohlich, Wien. klin. Rundschr., 15, 882-886, 906-908 (1901). 



