Abstract
The method herein described has been found to extract the active principle from bovine parathyroid glands in highly concentrated form.
Two to three grams of finely divided acetone, dessicated, defatted glands are triturated with one and one half volumes of three per cent hydrochloric acid, transferred to 1×8 Pyrex tubes, placed in a water bath, and maintained at a temperature of 70 to 75° C. for 20 minutes.
The extract is made faintly alkaline to litmus, then 0.3 per cent hydrochloric acid is added until a degree of acidity is produced such that the precipitate assumes a flocculent form, and settles rapidly, leaving a clear supernatant fluid.
Filtrate I is made up to a volume of 100 to 150 cc., adjusted to a pH of 5.5 to 5.8, and, sufficient anhydrous acetone added to bring to a concentration of 60 to 70 per cent in acetone. After standing 12 to 15 hours in the ice chest, precipitate II is separated from filtrate II.
Filtrate II is evaporated to dryness in vacuo at 40 to 45° C. The residue is dissolved in two and one half per cent trichloracetic acid, corresponding in volume to filtrate II. A finely divided precipitate slowly develops, and after standing 12 to 15 hours in the ice chest, is separated by centrifugalization, or if still in suspension, by filtration. It is then dissolved in strong alcohol and precipitated with anhydrous ether.
Eight to 20 milligrams of such a preparation have been found to produce an increase of 4 to 5 milligrams, in the plasma calcium of dogs ranging in weight from 12 to 19 kilograms, within 12 to 15 hours following subcutaneous injection.
The active principle has been extractea by liquid ammonia from the residue obtained by the evaporation of Filtrate II.
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