I. Effects of Injected Extracts of Fresh Pineal Glands of the Cow on Growth of Immature White Mice. ∗

Abstract

The rôle of the pineal gland in growth both before and after puberty is still a controversial subject, and it was with the hope of throwing some light on the question that these experiments were performed.

The mice used were bred in this laboratory from a selected standard stock, this procedure being essential to insure uniform results. Injections were begun after weaning at 21 days of age and continued for periods of 28 days. Conditions of diet, temperature, and cages were kept uniform for each group of 20 mice used. As a further check each litter was kept in a separate cage. Injections were made 3 times a week subcutaneously, each injection of 0.15 cc. containing 2 mg. of protein material and being equivalent to 0.03 gm. of gland. Weight measurements were made before each injection. In the preparation of the extract, sterile technique was used throughout except for sterilization of the extract itself, the method of preparation being to grind the material with twice its weight of clean sand, extract with distilled water and centrifuge. Control injections of sterile physiological saline were made.

At the end of 24 days of injection, during which time no retardation or acceleration of growth beyond that of the group of 20 control mice injected with physiological saline was observed, the mice, with no evidence of infection, showed a characteristic syndrome, became cachetic, and died within a day or two. To check again on the method of preparation and injection 2 additional series of 20 mice each were injected respectively with neutralized acid and alkaline extracts of the fresh gland of the cow. The protein content was made the same as before. In the case of the neutralized acid extract injections no cachexia or death was had at the end of a 28-day period.