Sparteine

SPARTEINE, an alkaloid which is a derivative of pyridine, with the formula C₁₅H₂₆N₂. Discovered in 1850 by Stenhouse from the herb Spartium scoparium L., growing in Central Europe. A colorless, transparent, thick oily liquid with a strong odor and a bitter taste, yellowing in air. Boils at a temperature of +325°. Sparteine dissolves well in alcohol, ether, and chloroform, and is very sparingly soluble in water. Being a strong base, sparteine combines with acids to form crystalline salts. The pharmacodynamic properties of sparteine were described in the most detail by Cushny and Fick. In its effect on the organism, sparteine is in many respects similar to nicotine and especially to coniine. In warm-blooded and cold-blooded animals, after some motor excitation—which probably depends on the irritation of tissues at the site of administration of the poison—sparteine causes a slowing of voluntary movements, weakening of reflexes, muscle twitching, and disorders of movement coordination. The animal becomes incapable of changing its body position: a frog placed on its back does not turn over onto its belly. Respiration becomes infrequent and superficial, the expiration phase is hindered, a pause appears between inspiration and expiration, during expiration the accessory muscles begin to act intensely, and finally respiration stops. Death ensues from asphyxia. The mechanism of sparteine poisoning, as Cushny's experiments showed, consists in the paralysis of the endings of the motor nerves of skeletal musculature, including the phrenic nerve. The proofs of this explanation are the following facts: first, the irritation of a motor nerve after the administration of sparteine does not cause the contraction of the corresponding muscle, whereas upon direct irritation of the muscle a contraction is obtained; second, when the iliac artery is ligated in a frog, sparteine does not cause motor disorders in the hind limb of the same side. Sparteine acts in a similarly paralyzing manner on the ganglia of the sympathetic nervous system and on the adrenal gland. Regarding the effect of sparteine on the circulatory apparatus, there are contradictory data in the literature. Most researchers have observed a slowing of the pulse, slowing of systole, and an increase in diastole from sparteine. Atropinization of the heart does not alter the effect of sparteine. The excitability and conductivity of the cardiac neuromuscular apparatus are decreased by sparteine, by virtue of which fibrillations of the cardiac muscle caused by various reasons sometimes disappear. Blood pressure, after a brief rise, decreases—on the one hand, as a result of the weakening of cardiac activity, and on the other hand, from the paralysis of sympathetic ganglion cells. In small doses, sparteine, according to Fick's opinion, paralyzes the endings of the vagus nerve. Some clinicians use sparteine as an agent regulating cardiac activity, and Sée even considered the effect of sparteine on the heart to be analogous to the effect of digitalis. This opinion, however, is currently considered incorrect. Indications by individual authors regarding the diuretic effect of sparteine have not yet been sufficiently verified. -- Preparations: Sparteinum sulfuricum, a crystalline substance soluble in water and alcohol. It is prescribed in powders, pills, and solutions from 0.004 to 0.2 per dose.