| Abstrakt: |
The absorption experiments were performed in the following manner: a cake of fresh yeast (Fleischmann) was suspended in 40 cc. of physiological salt solution, vigorously shaken for a few minutes, and centrifuged. The supernatant fluid was discarded. This procedure was repeated in order to remove extraneous matter present in the cake. The washed yeast cells were tested on a slide for viability by mixing a drop of the yeast suspension with a drop of Loeffler's methylene-blue solution and examining microscopically. Viable cells remained unstained, while dead cells readily took up the dye. Usually, only about 5-10% of the cells were stained. If the percentage of dead cells was higher, the cake was not used.The washed yeast cells were suspended in a mixture of 20 cc. of insulin U-40 of pH 3.5 and 60 cc. of saline. The suspension containing 800 units of insulin, or 10 units per cc, was allowed to stand for 2 hours at room temperature, occasionally stirred, and then centrifuged for 5 minutes at 1200 r.p.m. The supernatant fluid was decanted from the sediment and the latter washed once with 80 cc. saline in order to remove traces of the supernatant fluid, and then suspended in sufficient saline to make 80 cc. The insulin content of both the supernatant fluid and yeast cells suspension was determined in the usual way by injection into a series of fasting rabbits. The testing was performed several times with freshly prepared mixtures of insulin and yeasts. One cc. of the sediment suspension induced hypoglycemic shock in 12 of a series of 14 rabbits in from 2 hr. 10 min. to 4 hr. 50 min. The drop in blood sugar varied from 58 to 114 mg. %, with an average fasting glycemia of 98 mg. %, and an average glycemia during the shock of 24 mg. %. The minimal dose of yeast cell suspension which caused shock in 9 out of 12 fasting rabbits was 0.4 cc. to 0.6 cc. Inasmuch as that amount, according to the existing standard, corresponded to 3 units we may assume that 1 cc. of the suspension contained approximately 5-7.5 units of insulin. Control injections, with non-treated yeasts, failed to produce any change in the blood sugar. |
