Curarines
Curarines
alkaloids contained in the arrow poison curare.
The curarines in tube curare (from plants of the genus Chondodendrorn) are quaternary ammonium bases of tetrahy-droisoquinoline. Their most typical and most well-studied representative is (+)-d-tubocurarine choloride (C37 H42 N2 O6 -CI2), a colorless, water-soluble crystal with a melting point of 274°-275°C. Another variety of the curarines, contained in pot curare and calabash curare (from plants of the genus Strychnos), are alkaloids of the indole group. Their typical representative is C-curarine dichloride (C40H44N4OCI2), a substance closely related to strychnine.
Upon introduction into the blood, curarines cause disruption in the transmission of impulses from the motor nerve endings to the fibers of the skeletal musculature. The result is motor paralysis. This effect is brought about by chemical competition with acetylcholine, a transmitter of neural impulses, in bonding with the choline-receptor proteins of the postsynaptic membrane (which have a specific affinity for acetylcholine).
Introduction into the body of a solution of d-tubocurarine chloride or synthetic curarine substitutes (called curariform agents) for the purpose of causing temporary immobility of the musculature is called curarization and is used as a supplement to anesthesia in some surgical operations and in experiments on animals. Permissible curarine doses for human beings are 0.1–0.2 mg per kg.
REFERENCES
Katz, B. Nerv, myshtsa i sinaps. Moscow, 1968. (Translated from English.)Kharkevich, D. A. Farmakologiia kurarepodobnykh sredstv. Moscow, 1969.
Mikhel’son, M. Ia., and E. V. Zeimal’. Atsetilkholin: O molekuliarnom mekhanizme deistviia. Leningrad, 1970.
Curare and Curare-like Agents. Amsterdam-London-New York, 1959.
E. P. SEREBRIAKOV and T. M. TURPAEV