Total White Cell Counts of Peripheral and Heart Blood of the Rat

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Abstract
The action of alkali on carbohydrates produces light-absorbing substs. Similar absorption was produced when starch or starch fractions were dispersed in alkali and heated. A direct correlation between the amt. of absorption in the alkali reaction and the mol. wts. of the dextrose polymers involves certain conditions: (1) the same absorption group is produced in all cases; (2) the reaction occurs at an existing reducing end-group or at one produced by the action of alkali; and (3) the reaction per molecule continues to the same extent in a given time. Only the 3d requirement was not satisfied. Expts. were made with starch and starch fractions and with several comparison compds. Samples were heated for various times. Compds. with reducing end-groups produced in alkaline dispersion one or more compds. with a strong absorption band at 2820 A. When exposed to air, absorption decreased rapidly. If acidified, the peak shifted to 2550 A., and absorption did not decrease in air. Compds. with reducing end-groups produced the characteristic absorption, but compds. without these groups did not. Amylopectin was treated, acidified, and pptd. by ethanol. The absorbing compd. remained in the supernate and did not appear when the solid was redispersed in alkali. When the alkaline dispersion was heated a second time, no absorption developed. When the expt. was made with amylose, as much absorption was produced by the 2d treatment as by the first. The reaction is stopped by a structural difference in amylopectin. For maltose and low mol. wt. dextrin, the destruction from the alkali treatment was complete. Amylose retained 72% of its activity, and amylopectin 99%. Consequently the 3d condition was not satisfied. With maltose and dextrin, maximum absorption occurred in a few mins., while amylose took nearly 3 hrs. A fortuitous agreement was found between values of. E [image] and alkali lability numbers. If the values of E [image] are used to estimate relative molecular sizes, amylopectin is 19 times larger than amylose. Whole starch, calculated from absorption values, is 84% amylopectin and 16% amylose.

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