CHLOROPHENOL RED 



72 



CHLOINESTERASE 



outside the cells (Manery, J. F. and 

 Bale, W. F., Am. J. Physiol., 1941,132, 

 215-231; Manery, F. W. and Haege, 

 L. F., ibid, 134, 83-93). 



See, however, Heilbrunn, L. V. and 

 Hamilton, P. G., Physiol. Zool., 1942, 

 15, 363-374 for demonstration of chloride 

 in muscle fibers. 



If chloride is always extracellular in all 

 tissues it is possible accurately to meas- 

 ure the amount of extracellular fluid 

 and a new chapter in histochemistry is 

 opened. Lowry and Hastings give an 

 example. If rat muscle is found to 

 contain 10.5 milliequivalents of chloride 

 per kilogram of tissue and the serum of 

 the same animal 105.2 milliequivalents 

 of chloride per kilogram of serum water, 

 in view of the Donnan effect on chloride 

 distribution it can be calculated that a 

 kilogram of extracellular fluid contains 

 109.7 milliequivalents of chloride. Con- 

 sequently the sample of muscle contains 



10 5 

 rrr^ X 1000 = 96 gms. of extracellular 



fluid per kilogram. When the extra- 

 cellular fluid contains coUagenic and 

 elastic fibers, collagen and elastin must 

 be determined and the necessary correc- 

 tions made as well as for blood and fat 

 when these are present. When the in- 

 tracellular phase is chiefly composed of 

 a single type of cell as in skeletal or 

 cardiac muscle the further evaluation of 

 intracellular components is not diffi- 

 cult. Taking every known precaution, 

 evidence can apparently be collected of 

 the relative composition of extracellular 

 and intracellular phases. 



If it is desired to determine chloride 

 in very small amounts of fluid, as in 

 the analysis of glomerular urine, a 

 method described by Westfall, B. B., 

 Findlev, T. and Richards, A. N. (J. 

 Biol. Chem., 1934, 107, 661-672) is sug- 

 gested. Glick (p. 200) says this per- 

 mits chloride determination in a frac- 

 tion of a m1 of fluid containing 1 Mgni. 

 or less of the choride. The technique 

 of Sendroy, J. (Jr., J. Biol. Chem. 

 Chem., 1942, 142, 171-173) is adequate 

 for 10 (mI of serum. There are in addi- 

 tion several titrimetric methods for 

 chloride which should likewise be con- 

 sidered as possibilities. See Glick, pp. 

 281-283. 



Chlorophenol Red. See Hydrogen Ion Indi- 

 cators. 



Chlorophyll. The green pigment of plants 

 is a mixture of 2 substances chlorophyll 

 a and b, of which many derivatives are 

 known. In man several fluorescent 

 chlorophyll porphyrins are identifiable 

 in feces and urine. A detailed account 

 of chlorophyll is provided by Rothe- 



mund. P., in Glasser's Medical Physics, 

 1944, 154-180. 



Chloroplasts. Isolation and collection en 

 masse from spinach leaves by centri- 

 fugation (Menke, W., Zeit. f. Physiol. 

 Chem. , 1938-39, 257, 43. See Glick. 



Chloroprene, see Neoprene. 



Chlorothymols, as preservatives of gelatin, 

 glues, starches, etc. (Law, R. S., J. Soc. 

 Chem. Ind., 1941, 60, 66). 



Chocolate Blood Agar, see Bacteria, Media. 



Cholesterol (esters) = cholesterides. In 

 unstained frozen sections mounted in 

 syrup of levulose they show no color of 

 their own; but the Liebermann-Bur- 

 chardt Reaction in frozen sections of 

 formalin fixed tissue is positive. Digi- 

 tonine Reaction in similar sections 

 yields a complex in which the esters, if 

 present, will color with Sudan III and 

 lose birefringence in polarized light. 

 See Lipids tabular analysis, see Schultz 

 test for cholesterol and its esters. 

 Technique for determination in buffer 

 is given by Nieman, C. and Groot, E. H., 

 Acta Physiol, et Pharmacol. Neerland., 

 1950, 1, 488-501. 



Cholesterols (free). In unstained frozen 

 section mounted in syrup of levulose, 

 they show no color of their own. Lie- 

 bermann-Burchardt Reaction in frozen 

 sections of formalin fixed tissue is posi- 

 tive : blue, purple or violet then becom- 

 ing green. Digitonine Reaction in simi- 

 lar sections yields strongly birefringent 

 cr3-stals and rosettes which do not stain 

 with Sudan III. See Lipids, tabular 

 analysis. 



Choline. See Florence's Reaction for Semi- 

 nal Stains. 



Choline Deficiency. Use of fluorescence 

 microscopv in (Popper, 11. and Chinn, 

 H., Proc. Soc. Exp. Biol. & Med., 1942, 

 49, 202-204). See Vitamin B complex. 



Cholinesterase — Written bj' E. W. Demp- 

 sey, Dept. of Anatomy, Washington 

 University, St. Louis, February 26, 1951 

 — Important since it is implicated in 

 nervous transmission. It is present in 

 high concentration in the neuromuscu- 

 lar junction and in the electric organ of 

 eels, and has also been detected in the 

 axis cj4inder of nerves. Anfinsen, C. 

 B., O. H. Lowry and A. B. Hastings 

 (J. Cell, and Comp. Physiol., 1942, 

 20, 231-237) have developed a method 

 whereby the same section of rat brain 

 cortex can be stained for microscopic 

 examination and thereafter used for 

 enzyme measurement. Recently, a 

 number of techniques have been pro- 

 posed for its detection on slides. Go- 

 mori, G. (Proc. Soc. Exp. Biol, and 

 Med., 1948, 68, 354-358) reported that 

 long-chain fatty acid esters of choline 

 were hydrolyzed by tissue sections, and 



