PT  - JOURNAL ARTICLE
AU  - HENRY G. BARBOUR
AU  - CLYDE L. DEMING
TI  - II. PARADOXICAL ACTION OF· ANTIPYRIN IN PARTIALLY AND COMPLETELY DECEREBRATE RABBITS
DP  - 1913 Nov 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 149--184
VI  - 5
IP  - 2
4099  - http://jpet.aspetjournals.org/content/5/2/149.short
4100  - http://jpet.aspetjournals.org/content/5/2/149.full
SO  - J Pharmacol Exp Ther1913 Nov 01; 5
AB  - 1. Rabbits normally respond to antipyrin, in doses of 0.1 to 1 gram (sometimes as low as 0.06 gram) per kilo animal, by a fall in body temperature with marked peripheral vasodilation, and, where the dose is above 0.3 gram, with hyperpnea. Doses in the neighborhood of 1 gram per kilo may cause fatal convulsions. 2. The cerebrum and corpus striatum were removed from eighteen rabbits. In nine of these cases, being those exhibiting as a rule the fewest anatomical complications, a subnormal body temperature (32.5° to 37.5° the morning after operation) resulted. The remaining nine animals (besides two of the first mentioned nine, for the first four days after operation) behaved essentially like normal animals. The hypopyrexia animals showed signs of collapse, asymmetrical muscular disturbances, peripheral vasoconstriction and slow respiration. Their temperature condition was not due to cold, starvation, or hemorrhage but to a disturbance of central heat regulation, probably seated chiefly in the corpus striatum. When given 0.1 to 0.4 gram (per kilo) antipyrin they showed a definite rise in temperature rather than a fall, and a conspicuous absence of the vasodilation usually seen after the drug, as well as of the hyperpnea which would be expected from the larger doses within this range. Muscle stiffness was in evidence, bordering, with the larger doses, on tonic and clonic convulsions. 3. Animals completely decerebrated including corpora striata and optic thalami gave a temperature of 26.5° to 32.5° on the morning after operation. Antipyrin in doses below 0.33 gram per kilo had no effect upon these animals. Four-tenths gram and above always gave a definite temperature rise. Neither vasodilation nor high respiratory rates were seen. Muscle stiffness or tetanic spasms were noted.