584 VI. OCCURRENCE OF LIPIDS IN THE ANIMAL 



Holt 282 stated that the extent of fat storage in the liver of a female with 

 congenital idiopathic hyperlipemia was considerably greater than in the 

 case of two brothers who also suffered from this abnormality. 



Another expression of sex difference in lipid storage is to be found in the 

 studies of Lorenz, Chaikoff, and Entenman. 283 These workers reported 

 that the level of neutral fat was much higher in the livers of laying hens 

 than in non-laying hens or in male birds. Although no similar variation in 

 phospholipid and cholesterol obtained in the liver under these conditions, a 

 significant increase in the values of these lipid components, as well as of 

 neutral fat in the blood, was noted. 



Loeb and Burr 284 reported that the fatty acids in the neutral fats of the 

 rat carcass are selectively affected by sex. Thus, although no sex differ- 

 ences could be established in the degree of unsaturation of fatty acids ob- 

 tained from the body fat of rats raised on diets of 20% lard, hydrogenated 

 coconut oil, or on fat-free diets, it was reported that, on a high-fat diet de- 

 ficient in essential fatty acids, females stored more fat than did males. It 

 was suggested that the males are more sensitive to a deficiency in essential 

 fatty acids than are females, when both derive the bulk of their calories 

 from fat. 



(d) The Effect of Ovariectomy on the Distribution of Storage Fat. It is 

 generally agreed that removal of the ovaries results in obesity. For ex- 

 ample, Stotsenburg 285 reported that ovariectomized rats presented more 

 fat at autopsy than did the non-spayed control rats. Slonaker 286 likewise 

 noted that castrated female rats had a greater increment in body weight 

 than did normal animals, but he suggested that this could be attributed to a 

 greater increase in body length as well as to fatness. On the other hand, 

 Marshall 287 did not note any marked tendency to fattening in ovariecto- 

 mized rats. Finally, Reed, Anderson, and Mendel 288 reported a slight in- 

 crease in body fat, together with a very considerable increase in body 

 weight, following the removal of the ovaries. However, a marked decrease 

 in genital fat was observed in the operated animals, which was compensated 

 for by a proportionate augmentation of the subcutaneous fat. These ex- 

 periments are summarized in Table 13. 



282 L. E. Holt, Jr., personal communication to the author, 1953. 



283 F. W. Lorenz, I. L. Chaikoff, and C. Entenman, J. Biol. Chem., 123, 577-585 (1938). 



284 H. G. Loeb and G. O. Burr, J. Nutrition, 33, 541-551 (1947). 



285 J. M. Stotsenburg, Anat. Record, 7, 183-194 (1913). 



286 J. R. Slonaker, Am. J. Physiol, 93, 307-317 (1930). 



287 F. H. A. Marshall, The Physiology of Reproduction, 2nd ed., Longmans, Green, 

 London-New York, 1922, pp. 390, 391. 



288 L. L. Reed, W. E. Anderson, and L. B. Mendel, J. Biol. Chem., 96, 313-323 (1932). 



