ENZYMES CONCERNED WITH DIGESTION OF LIPIDS 49 



the liver and blood contained both the true and the pseudocholinesterases, 

 the sex variation apparently was confined to the s-variety. Since castrates 

 of either sex respond to the administration of estrogen by elevations in 

 liver and blood s-enzyme, it was concluded that the liver is the site of 

 synthesis of pseudocholinesterase. Harrison and Brown 273 also reported 

 that livers of female rats exhibited a very high cholinesterase activity which 

 was maintained by the ovarian hormones. The greater part of this 

 increased content of cholinesterase in the female disappeared when the 

 normal functions of the liver had been disturbed by fasting for two days, or 

 by poisoning. The liver of the male was shown to have a much lower initial 

 enzyme content; by the end of the second day of fasting, however, the 

 difference had largely disappeared. These workers conclude that, in the 

 female, there exists in the liver a considerable cholinesterase activity which 

 is labile, sex-linked and, in some way, different from the slight basal activ- 

 ity common to both sexes and closely associated with liver proteins. The 

 decrease in serum cholinesterase during fasting is believed to reflect the 

 fact that the serum cholinesterase originates in the liver; when the liver 

 content is reduced, a concomitant decrease in level would be expected in 

 the serum. 



A number of workers 276-278 have demonstrated that the s-cholinesterase 

 in mouse and rat livers is influenced by sex hormones. It has likewise 

 been proved that the same sex hormones have a marked effect on the level 

 of serum cholinesterase of man, rats, cats, and guinea pigs. 278 ~ 282 



Nutritional status likewise has an important bearing on the level of 

 cholinesterases. Davies and Rutland 272 found that the mean cell cholin- 

 esterase content of a group composed of service men who were in excellent 

 physical condition was significantly higher than that of the regular blood 

 donors. However, Saunders et al. 2 * 3 are of the opinion that the level of this 

 enzyme is of dubious value as an index of nutritional status. In examina- 

 tions on 119 children, no useful correlations could be found between serum 



276 H. Birkhauser and E. A. Zeller, Heir. Chim. Acta, 23, 1460-1464 (1940). 



277 E. A. Zeller and H. Birkhauser, Heir. Chim. Acta, 24, 120-126 (1941). 



278 E. A. Zeller, H. Birkhauser, H. v. Wattenwyl, and R. Wenner, Helv. Chim. Acta, 

 24, 1465-1470(1941). 



279 E. A. Zeller, H. Birkhauser, H. v. Wattenwyl, and R. Wenner, Helv. Chim. Acta, 

 24, 962-968 (1941). 



280 H. v. Wattenwyl, A. Bissegger, A. Maritz, and E. A. Zeller, Helv. Chim. Acta, 26, 

 2063-2070(1943). 



281 J. W. Everett and C. H. Sawyer, Endocrinology, 39, 323-343 (1946). 



282 C. H. Sawyer and J. W. Everett, Endocrinology, 39, 307-322 (1946). 



283 J. P. Saunders, H. R. Sandstead, R. E. Butler, and O. Mickelsen, ./. Nutrition, 47, 

 191-201 (1952). 



