The effects of morphine, diacetylmorphine and some related alkaloids upon the alimentary tract: Part I. Stomach and pylorus

Abstract

1. The effects of morphine and diacetylmorphine upon the stomach of the cat are variable. The greater number of experiments showed a decrease in tone which was accompanied by a decrease in the frequency and amplitude of movements. Some animals showed an increase in stomach tone accompained by three to five slowly moving contractions of great amplitude while no change were recorded in two cats.2. Codeine sometimes produced a slight increase in the amplitude of stomach movements with a diminished frequency, while at first the general tone is unaltered. Tone is later reduced slightly to a subnormal level. In other cases it causes a very slight increase in tone and amplitude of movements. These effects are short lived and very small when compared with those produced by morphine or heroin.3. The effects of dihydromorphinone (dilaudid) upon the stomach are far from constant. Most animals show an immediate relaxation of the stomach with a decrease in the amplitude of the movements. In a series of nine experiments, six showed relaxation of the stomach, two contraction, and in one no changes were recorded.4. The effects of dihydrocodeinone (dicodid) on the stomach resemble those of codeine. They consist of a small gradual increase in tone followed by a relaxation to a subnormal level.5. Dihydro-oxycodeinone (eukodol) produces effects which resemble those of dihydrocodeinone (dicodid).6. All these drugs produce constant effects upon the pyloric sphincter. They all produce an increase in the tone of the sphincter accompanied by an increase in the amplitude of the rhythmical movements. Dilaudid is approximately eight times more active than morphine, while diacetylmorphine is about one and a half times more potent than morphine. The effects of these three drugs last several hours.The effects of codeine, dicodid and eukodol show a great similarity. They are of short duration and very small when compared with morphine, heroin and dilaudid.