The Production of Shock in Rats by the Drum Method. ∗

Summary

1. Varying degrees of shock can be produced in rats by subjecting them to various periods of trauma in Noble-Collip drums. The method appears to be suitable for use where graded and reproducible degrees of trauma are desired.

2. The percentages of survival were: for 5 minutes of tumbling, 100%; for 8 minutes, 65.6%; for 10 minutes, 71.4%; for 12 minutes, 47.2%; for 13 minutes, 9.5%; and for 15 minutes, 4.3%.

3. The Sprague-Dawley strain and a cancerresistant strain of rats were found to be less resistant to trauma of the Noble-Collip type than were rats used by other investigators.

4. Survival of previous hemorrhage did not increase resistance to Noble-Collip trauma, but appeared to decrease resistance to some extent.

5. Adrenal enucleation decreased the resistance of rats to Noble-Collip trauma although regeneration of cortical tissue had been sufficient to support normal growth and to maintain the rats in a healthy state.

6. Protection to the abdomen and taping of the paws gave only limited protection to the rats of the Sprague-Dawley strain subjected to Noble-Collip shock.