The Physiological Rôle of Vitamin B

Abstract

The daily administration of 1 gm. of yeast extract to pigeons during inanition did not prevent hypertrophy of the adrenals. In most cases the adrenaline content of the glands was increased proportionately to the hypertrophy. A slight hypergly-caemia was observed during inanition, which was not prevented by administration of yeast extract. Later a sharp fall in blood sugar level, coinciding with the pre-mortal fall in body temp., was also observed. Nervous symptoms, resembling those due to vitamin B deficiency, were observed in starving pigeons. These occurred only when the blood sugar and body temp. were much reduced, just before death. The incidence or severity of these symptoms was not increased by daily administration of large volumes of water. The symptoms could not be due to vitamin B deficiency since they also occurred in birds receiving yeast extract daily. Birds forcibly fed with vitamin B deficient diet developed the nervous symptoms more rapidly than those feeding voluntarily on the same diet. In this manner the loss of weight due to lowered food consumption was eliminated. The adrenals of these birds were hypertrophied, but their adrenaline content was not increased, as in starvation. No satisfactory explanation of these results is presented.