On the function of torulin. An <i>in vitro</i> effect of antineuritic vitamin concentrates

Abstract

have shown that there is a lowered oxygen uptake' as compared with the normal in pieces of minced avitaminous pigeon's brain tissue suspended in glucose-phosphate solution2. The change was most marked in the optic lobes. Cure of the pigeon was accompanied by an increase in oxygen uptake, at a time when no increase in body weight occurred. This was proof that a change had occurred in the tissue as the result of introducing vitamin into the body, but not that the increase was due to the addition of vitamin as such to the tissue. Two things suggest that the changes in avita- minosis were due to the local lack of vitamin: (1) that the changes in the brain tended to be localised, and (2) that the most rapid cures of head retraction observed in this Department were induced by the injection of torulin into the cranium; in some cases indeed cure of symptoms has occurred in 30 minutes. Striking as this evidence is, it is not conclusive. The missing entity in the tissue, indicated by the localjsed chemical lesion, might be some hormone either made from the vitamin and brought to the brain in the circulation, or secreted as the result of a stimulus of vitamin. It has in fact been stated by Cramer [1930] that vitamin B extracts cause a rapid liberation of adrenaline from the suprarenal gland. Such an explanation might also apply to the injection experiments. There are two ways of settling the question; either it might be proved that there is less vitamin B, in the optic lobes, etc. than normal, which is not practical with the pigeon test owing to the small amounts of tissue involved, 1 We prefer to use the expression "oxygen uptake" which exactly expresses the observations and is at present non-committal as to their meaning.