“Experiments with some saline purgatives given subcutaneously”

Abstract

In spite of the large amount of work which has been done regarding the effect of subcutaneous and intravenous injections of saline purgatives, investigators are still in disagreement. To mention only the most recent writers, MacCallum 1 claims that “all these salts which act as purgatives when introduced into the stomach or intestines have the same action when injected subcutaneously or intravenously.” Eckhardt 2 on the other hand, states that “Die Mittelsalze haben bei unseren Haustieren keine abführende Wirkung” and that “Im Gegentheil wirken sie, auf diesem Wege einverleibt, häufig verstopfend.” Both authors used approximately the same dose, injected the same salts subcutaneously and intravenously and yet arrived at diametrically opposite results.

In an extensive series of experiments already published, Meltzer and the author 3 have shown, among other things, that the subcutaneous injection of magnesium sulfate does not produce purgation. In view of the peculiar properties of magnesium salts the investigation was extended to some of the other saline purgatives.

In this investigation rabbits weighing about 1,500 grams were used and the salts chiefly employed were sodium sulfate and sodium phosphate. Sodium sulfate, in 4 per cent. and 25 per cent. solutions, when injected subcutaneously in 15 C.C. doses, caused no purgation in any of the experiments, Five or six hours after an injection, the feces that were passed often weighed less than five grams and were of normal consistence and form. Only rarely did the total 24-hour fecal output exceed 15 grams and the pellets were moderately hard, dry and well formed, Similar results were obtained when 4.5 per cent. sodium phosphate, in 15 C.C. doses, was injected subcutaneously. Both salts failed to cause purgation but induced a moderate degree of constipation.

The action of sodium sulfate and sodium phosphate on intestinal peristalsis was also studied. The intestines of rabbits anesthetized by morphin were observed with and without a saline bath.