Two methods for recording oscillatory movements in mice have been developed. The first method uses a permanent dynamic speaker, on which a mouse cage is placed. The second one is an assembly consisting of an accelerometer using strain gauges, a small bar for placing the mouse on it and attaching the accelerometer and a support-ing stand for the bar. The output from the speaker or the accelerometer is fed to an apparatus for electroencephalography or to a tape recorder. The data stored in the tape are analyzed by an electric filter. Tremorine was used as an inducing agent for oscillatory movements. Tremor in-duced by tremorine was characterized as follows: (1) the increase of immobile periods, (2) the derease of movements with high frequencies such as over 25 cps, and (3) the intermittent appearance of movement with specific frequencies between 14-25 cps. From the viewpoint of easiness in finding tremor, the second method has been considered to be better than the first, because of a clear discriminative ability for tremor from other oscillatory movements recorded.
Methemoglobin formation in the blood of animals injected with nitroglycol has been reported by many investigators, although such phenomena have not yet been observed in dynamite workers. In this paper the mechanism of methemoglobin forma-tion was studied kinetically, and the overall reaction was found to be as follows;
An enzyme, which catalyzes the decomposing reaction of nitroglycol or nitroglycerin into inorganic nitrate and ethylene glycol mononitrate, was found in the blood and in the liver. This enzyme was named as " Nitrate forming enzyme ". Both the enzymes in the blood and in the liver showed the same properties, but they were clearly dif-ferent from nitrite forming enzyme reported by Heppel and Hilmore. Nitrate forming enzyme was extracted from acetone powder of the liver and par-tially purified by ammonium sulfate fractionation. The value of Michaelis constant of the enzyme was about 3.0 mM at pH 7.4 and 37°C, and the value of optimum pH was 6.3. This enzyme acts on nitroglycol without reduced glutathione (GSH) as a co-factor, although nitrite forming enzyme can not act in the absence of GSH. A significant property of this enzyme is the inactivation by the substrate itself, and it appears at very low concentrations of nitroglycol.
We have found a new enzyme named nitrate forming enzyme which catalyzed the production of inorganic nitrate from nitroglycol or nitroglycerin in the blood and in the liver. On the other hand, the presence of nitrite forming enzyme in the liver has been known, though the mechanism of enzyme reaction was obscure. In this report, we investigated kinetically the reaction mechanism of nitrite forming enzyme by using nitroglycol, nitroglycerin and other nitrite or nitrate esters as substrate. Clark and Litchfields' scheme for explaining the decomposition of nitroglycol, which was, in fact, proposed as the metabolic path of nitroglycol in the body, was found to be unsuitable, because the main compound in their scheme, nitrite ester, was clarified to be not formed during the decomposition of nitroglycol. Instead of their scheme, we have proposed a new scheme.
In attempt to know the effect of 2, 4, 5-T on energy metabolism, the following re-sults were obtained. 1. 2, 4, 5-T inhibited the oxygen uptake of mouse liver slices at the concentrations of 10-4M to 10-3M. Lower than 10-5M, it seemed to be indifferent to the oxygen uptake. 2. At the concentrations of 5×10-5M to 5×10-4M, 2, 4, 5-T was shown to be an un-coupling agent for oxidative phosphorylation and to stimulate the respiration of rat liver mitochondria in the medium lacking hexukinase. 3. The latent ATPase of the intact mitochondria was activated by 2, 4, 5-T and oligomycin diminished its effect. 4. With various respiratory-chain inhibitors and artificial electron doners and acceptors, it has been demonstrated that 2, 4, 5-T interfered the phosphorylation mechanism equally at any one of the three phosphorylation sites. Upon these observations, mechanism and site of action of 2, 4, 5-T have been briefly discussed.