Blood Diastase as an Indicator of Liver Function

Abstract

The method developed in this laboratory for the estimation of diastase in biological material satisfies 2 essential requirements: it yields accurate quantitative results, and is sufficiently sensitive to permit the determination of very small quantities of the enzyme.

The quantity of the enzyme we express as the amount of reducing matter, in terms of glucose, which is produced by a known amount of the enzyme-bearing material under standardized conditions. As applied to blood, when we state that the diastase value of human blood serum is on an average 120, this means that 100 cc. of serum, incubated with 1.5% starch paste for 1/2 hour at 40°, produces a quantity of reducing matter which in regard to reducing capacity is equivalent to 120 mg. of glucose. The determination is actually carried out with 1 cc. of plasma (or serum), which is incubated with 5 cc. of starch paste and 2 cc. of a 1% NaCl solution for 30 minutes, and subsequently deproteinized by our copper method. The reduction value determined in the filtrate, minus the original sugar content of the plasma, represents the diastase value. From the normal average figure of 120 considerable deviations are found in either direction. The lowest value is, with very few exceptions, 80, the highest about 180. But, while individual variations spread over a considerable range, the blood diastase of one and the same individual shows a remarkably constant level; it is, moreover, largely independent of nutritional factors and does not change even over periods of months and years.

During the past 2 1/2 years we have been running blood diastase determinations on nearly 100 healthy persons and several hundred hospital patients, in order to gather information in regard to possible deviations from the normal values.