THE EFFECT OF ERGOTAMINE ON THE INTESTINE WITH OBSERVATIONS ON THE INFLUENCE OF CALCIUM ON ITS ACTION

¹ From the Biological Laboratory, Cold Spring Harbor, Long Island, New York

1. A single dose of ergotamine injected intravenously produces in cats and rabbits increased movements of the intestines. The effect may be obtained with doses of about 0.1 mgm. per kilogram in cats and smaller doses in rabbits. The same amounts may sometimes produce a weak response or no effect when respiration is depressed, irregular or both.

2. Repeated doses of ergotamine cause little or no effect or may even produce inhibition of the intestine.

3. Atropine prevents the stimulating action of the intestine by ergotamine indicating that stimulating is due to the effect on the parasympathetic endings.

4. The effect of multiple injections is probably due to depression of the muscle substance and fatigue of the nerve endings.

5. Reversal of the depressing action of repeated doses of ergotamine, may be produced by intravenous injections of calcium chloride.

6. Intravenous injections of sodium oxalate which produce a decrease of blood calcium increases the depressing action caused by ergotamine and may also decrease the stimulating effect of the initial dose.

7. The effect of excess and of deficient calcium on the action of ergotamine was discussed and an explanation was suggested.