October 15: Condition of rabbit good; no symptoms.
Rabbit 191. Brown male. Weight, 1,915 grams. Diet, oats.
October 14: 16 cc 2 per cent caffein (167 mg per kilo) injected subcutaneously; reflexes increased and tremors present.
October 15: Condition of rabbit good.
A study of this series shows that about 150 mg of caffein per kilo caused increased reflexes within one to two hours after injection. When the dose was increased, as in rabbits 194 and 191, the symptoms were more pronounced; 150 mg per kilo may be regarded as the minimum dose which produces symptoms of nervous irritability when caffein is injected subcutaneously. Experiments with larger doses were therefore carried out in order to determine the minimum fatal dose.
Series B.
Approximately 0.2 gram of caffein per kilo was employed in these experiments. Diet and race as possible factors which may influence the toxicity of caffein were made the subject of study in these experiments which were divided into two groups as shown in the table, [page 25].
Rabbit 95. Gray and white male. Weight, 1,478 grams. Diet, oats.
February 27: 11.30 a. m., 15 cc 2 per cent caffein (210 mg per kilo) injected subcutaneously; 2.20 p. m., no symptoms, tremors observed when handled, but not marked, reflexes slightly increased, no muscular rigidity nor any other symptoms; 2.45 p. m., rabbit suddenly became very restless, jumped off the table, and had convulsions; 3.45 p. m., rabbit died, rigor mortis set in almost immediately after death.
Rabbit 96. Gray and white male. Weight, 1,585 grams. Diet, oats.