Antitryptic Titre in Pregnancy and in Hyperthyroidism.

Abstract

Since it is known that the normal blood serum contains substances which inhibit the action of enzymes, and that the titre of such substances varies, there is ground for supposing that this property of the blood plays some physiological rôle. Specifically it might be conjectured that it affects catabolism and that in conditions where changes in metabolism are an outstanding feature correlated changes in antienzyme titre would be found, and that these might have etiological import. Indeed, fragmentary observations of changes occurring in pathological conditions have been made. 1 , 2 , 3

With this thought in mind we investigated two conditions in which metabolic changes were prominent: (1) pregnancy, (2) toxic hyperthyroidism. The method used follows Northrop and Hussey. 4 5 cc. of a 1% solution of commercial pancreatin were mixed with 0.5 cc. of serum to be tested; 0.5 cc. of the mixture was then added to 10 cc. of a 3% solution of commercial gelatin in an Ostwald viscosimeter and the viscosity changes noted at 35° C. Two of us have shown elsewhere 5 that under these conditions the viscosity changes may be represented as a logarithmic function and that the exponential rate is linearly related to enzymatic activity. Accordingly the exponential rate of viscosity change was obtained for each serum examined and compared with one or more normal sera observed at the same time. As a measure of the antitryptic titre we use the difference between the rate obtained for the experimental serum, and that obtained for the normal serum which was run in the same bath, and this expressed as a percentage of the control rate, a plus sign indicating an experimental serum the titre of which is greater and a negative one which is less than the normal control.