Ruth Guild

Galorigenic Action of Methylene Blue During Muscular Exercise.

In previous communications (Rapport, 1 Canzanelli, Segal and Rapport 2 ) we have presented evidence indicating that while the energy of the calorigenic action of certain substances, (such as protein, certain amino acids, thyroxine, etc.) can not be used as a fuel for muscular work, that of carbohydrate and fat could be so used. The present communication deals with similar observations in regard to methylene blue, a substance foreign to the body, which, when administered, has a considerable effect on the total metabolism. The experiments were made on a single well-trained female dog, weighing about 9 kilos, and subsisting on a constant maintenance diet, the methods being the same as those used in the above mentioned researches. The gaseous exchange was obtained in a closed system, into which, for the purpose of exercise, a horizontal treadmill was introduced. Exercise consisted of 15 minutes running at about 2.5 kilometers per hour, and the metabolism of exercise and recovery was calculated by computing the amount of respiratory exchange in excess of that at rest. This was done both on days when the resting metabolism was basal, and on days after the injection of 10 mg. of methylene blue in one percent watery solution per kilo of body weight. Three alcohol checks were performed during the course of the work, the respiratory quotients being 0.660, 0.667 and 0.671 respectively, the maximum error in the R.Q. being 0.007, or about one percent. The results are shown in Table I. In 4 experiments under “basal” conditions, the resting metabolism was 11.9 cal. per hour. When the animal was exercised, there was an “extra” metabolism which averaged 1.81 ± 0.07 gm. cal. per “horizontal” kilogrammeter of work. After giving methylene blue, the resting metabolism averaged 16.9 cal. per hour, an increase over the basal of 42%.