Negative Effect of Chronic Morphinism on the Anorexia Characteristic of Vitamin B 1 Deficiency. ∗

Abstract

Certain observations made by Dr. Henry G. Barbour on dogs receiving repeated doses of morphine suggested that the anorexia exhibited by such animals might be due to some effect of the continued morphine administration on the organism's requirement for vitamin B₁. The perfection of a technic for studying in dogs the anorexia characteristic of lack of this vitamin made it possible to study this suggested relationship experimentally.

The method employed has been used successfully for many studies from this laboratory 1 and therefore need not be described here. Certain details pertinent to the investigation here reported should be mentioned, however. Our Casein III 2 B₁-free diet was used as the basal ration. At the beginning of a feeding trial the animal received several large daily doses of either dried yeast or wheat germ in order to “saturate” the tissues with the vitamin and in this way obviate any possible effect of the previous dietary regime. The number of days between cessation of such vitamin administration and the appearance of the characteristic anorexia was then noted, and the effect of a given dose of test substance in restoring the urge to eat then observed. Since the pure vitamin was not available at the time, several products were used. Although these differed in origin, they were alike in that they were good sources of vitamin B₁. Their values in this respect were determined by separate assay on pigeons. 3 The test substances were dried yeast,† wheat germ,‡ and an adsorbate similar to the international standard (1934) but made with Lloyd's reagent instead of ordinary fullers earth.§ In a few instances a concentrate,| which could be given parenterally when necessary, was tried.

After each of the 3 widely different sources of the vitamin had been tested on 7 dogs under “normal” conditions, the animals were fed a stock diet and morphine administration begun.¶