Some effects of phosphates parenterally administered.

Abstract

Embden, Griesback and Schmitz, 1 Witzemann, 2 Winter and Smith 3 and others seem to have demonstrated that phosphates, both organically and inorganically bound, play an important rôle in carbohydrate metabolism. It thus becomes of interest to know whether inorganic phosphates parenterally administered influence this metabolism as mirrored by blood sugar changes.

Our experiments show that when ortho-phosphoric acid (0.2-2.0 cc. U. S. P. acid in 10 cc. water), mono basic sodium phosphate (1.0-4.0 grams dissolved in the least amount of water), dibasic sodium phosphate (0.5-2.0 grams) and the tribasic sodium phosphate (1.0-3.0 grams) are injected subcutaneously in rabbits (weight 1000-1300 grams) the blood sugar practically always shows a very marked rise. The increased sugar is apparent within twenty minutes, and lasts as a rule for two hours or more. Acid sodium phosphate tends to produce the highest blood sugars when compared with the dibasic and tribasic salt on a weight of salt per kilogram body weight basis; the tribasic is least effective in this respect. The blood sugar rise does not appear to parallel the appearance of the convulsions or tetany to be discussed below, inasmuch as many of the animals showed high blood sugar with no nerve symptoms, and vice versa. Further-more, a given dose of phosphate in two animals of the same weight does not necessarily produce comparable blood sugar elevations.

Binger 4 has demonstrated that Na₂HP0₄, and Na₃P0₄, given intravenously, produce tetany, but NaH₂P0₄ is inactive in this respect. Tisdall 5 and Kobert 6 found H₃Po₄ equally ineffective.

Our results'confirm these data and further show that NaH₂P0₄ produces marked opisthotonic convulsions. The orthophosphoric acid does not produce convulsions or tetany within the limits in which we have worked-death by respiratory paralysis ordinarily ends the experiment before symptoms become manifest. It would thus appear that either by a change in the [H⁺] or by the addition of the Na⁺ or by both we can obtain a wide variation in symptoms (1) sudden death with very few nervous manifestations (H₃P0₄); (2) violent convulsions (NaH₂PO₄); (3) tetany (Na₂HP0₄) and (Na₃PO₄).