02 II. DIGESTION AND ABSORPTION OF FATS 



between pseudocholinesterase and true cholinesterase levels in the blood; 

 moreover, it was impossible to demonstrate any correlation between the 

 cholinesterase in serum and in the cerebrospinal fluid. Although, in some 

 cases, the serum cholinesterase level was increased after electroconvulsive 

 treatment, repeated shocks always resulted in a decreased level. 



In traumatic shock, the intravenous injection of cholinesterases caused 

 restoration of the blood pressure to normal. Schachter 298 suggests that 

 this effect may be due to a shift of fluid from the tissue to the blood stream, 

 with a resultant increase in plasma volume, or to the destruction of any 

 increased acetylcholine which might result in dilatation to such an extent 

 that fluid would leave the vascular bed. Burn et a/. 29y reported that the 

 cholinesterase content falls by 40 to 50% in the jejunum and ileum forty- 

 eight hours after x-irradiation. 



It has been suggested by Vincent and Parant 300 that the ratio of true to 

 pseudocholinesterase in serum may be of importance in various diseases, 

 especially those of the nervous or mental type. The highest level of true 

 cholinesterase in the serum was reported in a case of generalized cancer. 



(g) Distribution of Cholinesterases. Cholinesterase is widely distributed 

 throughout the animal body. Most tissues contain both the e (true) and 

 the s (pseudo) variety of cholinesterases. Whittaker 301 has recently sum- 

 marized the distribution of cholinesterase in various tissues, with special 

 emphasis on the specific varieties of the enzyme present. 



a'. Cholinesterases in Blood: The blood ordinarily contains two types of 

 cholinesterase, the s-variety in the serum and the e-type in the erythro- 

 cytes. While the s-type has been demonstrated in the sera of man, guinea 

 pig, and the horse, it is absent from that of the ruminants. 302 Adams and 

 Whittaker, 303 using a method based upon comparing inhibition with DFP 

 and with di-(2-chloroethyl)methylamine hydrochloride (DDM), evidence 

 was adduced for the presence of a second enzyme in plasma, DFP- and 

 DDM-insensitive, which accounts for 5 to 20% of the aliphatic esterase 

 activity of the plasma, and which also hydrolyzes triolein. Sturge and 

 Whittaker 304 found that cholinesterase in horse plasma resembles that in 

 human plasma in hydrolyzing a large number of aliphatic esters. It was 

 concluded that cholinesterase and ali-esterase, in spite of their close associa- 



298 R. J. Schachter, Am. J. Physiol., US, 552-557 (1945). 



299 J. H. Burn, P. Kordik, and R H. Mole, J. Physiol, 116, 5P-6P (1952). 



300 D. Vincent and M. Parant, Compt. rend. soc. biol, US, 1093-1095 (1949). 



301 V. P. Whittaker, Physiol. Revs., 31, 312-343 (1951). 



302 J. M. Gunter, Nature, 157, 369 (1946). 



303 D. H. Adams and V. P. Whittaker, Biochem. J., U, 62-70 (1949). 



304 L. M. Sturge and V. P. Whittaker, Biochem. J., 47, 518-525 (1950). 



