The action of succinate,malate,tartrate and citrate on the isolated intestine

Abstract

Segments of the isolated intestine of the rabbit suspended in Locke's solution and containing sodium succinate exhibited increased activity in concentrations of N/30 to N/200. Stimulation was also observed in N/10 succinate, but this was usually preceded by primary depression. Sodium malate in concentrations of N/10 and N/30 caused depression, the rhythmic contractions disappearing almost entirely for a period of several minutes. This was followed, however, by improvement while the intestinal segments were still in contact with the salt. Stimulation was observed in tests with N/70 to N/100 sodium malate. Sodium tartrate dextro in Locke's solution produced the following results: A solution of N/10 made up by adding the salt to Locke's solution caused promptly a drop of tonus; rhythmic contractions became weak or disappeared entirely for a few minutes. The fact was less marked, however, with the same concentration of tartrate when it was substituted for an equivalent amount of sodium chloride. In this case a moderate decrease only of amplitude without a change of tonus in the small intestine was noticed. The large intestine showed a marked decrease of tonus and complete disappearance of rhythmic contractions. With weaker concentrations of tartrate, such as N/20 to N/50 a decrease of tonus was obtained, which was greater in segments of the large intestine, the effect diminishing with increase in dilution. The rhythmic contractions were usually augmented in force, especially in the ileum, the effects being the same with isosmotic and with hypertonic solutions.

Observations on the action of citrate indicated that a solution of N/400 may increase the force of the contractions and sometimes also the tonus. The effect was different with more concentrated solutions. Tonus was depressed in practically all cases. Although the amplitude of the rhythmic contractions showed considerable augmentation with a solution of N/200, this was often preceded by a preliminary decrease.