Effects of Aconitine in the Rat.

Abstract

The primary purpose of these experiments was to determine the effects of aconitine on the pulse rate of the rat. In addition the lethal dosage was determined. Commercial crystalline aconitine (Lilly) was used.

In order to reduce bodily movements the rats were given 0.6 cc. of a 15% solution of urethane per hundred gm. of body weight. After the pulse rate had become constant various dosages of aconitine were injected intraperitoneally and the heart rate taken by an ausculatory method. 1 The dosage of aconitine administered in each case is stated in terms of mgm. per 100 gm. of body weight. What was estimated to be a lethal dose of aconitine, 0.032 mgm., was administered to each of 3 rats under urethane. One rat died in 41 minutes, the second in 79 minutes, while the third lived over 120 minutes.

Ten animals were given 0.0064 mgm. Under urethane the average heart rate was 337 beats per minute. Following the administration of the alkaloid the average of more than a hundred determinations was 334 beats per minute. There was, therefore, no significant effect of the aconitine on heart rate. Similar results were obtained with 3 rats under amytal anesthesia.

Following urethane one rat was given 0.0128 mgm. and 3 others were given 0.0256 mgm. of aconitine. The heart beat became irregular in each of these animals.

Experiments were made to determine the minimum fatal dose of the alkaloid. No anesthetic or sedative was used. Two adult rats received 0.0256 mgm. and died within 2 hours. Two rats receiving 0.0192 mgm. and 2 rats receiving 0.0227 mgm. developed serious respiratory and heart disturbances but recovered. These data indicate that 0.026 mgm. is a lethal dose for the rat, while the minimum fatal dose is approximately 0.025 mgm.