ACTIONS OF KURCHICINE, AN ALKALOID OF HOLARRHENA ANTIDYSENTERICA

¹ From the Pharmacology Laboratory, Oxford University

The approximate M.L.D. per kilogram by subcutaneous injection is, for the frog 0.051 gram, and for the guinea pig 0.088 gram. The M.L.D. per kilogram by intraperitoneal injection for the mouse is about 0.160 gram.

Toxic doses produce paralysis of the central nervous system in frogs but this effect was somewhat less marked in the guinea pigs.

Small doses of kurchicine produce a rise of blood pressure followed by a fall which is recoverable. Larger doses cause a permanent fall in blood pressure due mainly to its toxic action on the cardiac muscle. Kurchicine constricts the coronary vessels in the isolated rabbit’s heart. Kurchicine constricts the kidney vessels and dilates those of the intestine.

Kurchicine has a depressing action on the isolated gastrocnemius muscle of the frog even in a concentration of 1:40,000. The smooth muscle of the intestine and uterus is stimulated by kurchicine.

Kurcbicine has a very low toxicity for Paramoecium caudatum, a concentration of 1:2500 failing to kill them in three hours. The minimum concentration of kurchicine which killed Amoeba proteus in three hours is 1:5000.