The influence of mental load upon the physiological functions was studied by measuring the urinary output of adrenaline and noradrenaline and by recording the heart rate con-tinuously by cardiotachograph on 10 healthy adolescents (average 24 years) and 6 normal middle-aged men (average 52 years) during a continued arithmetical calculation test (Kraepelin-Uchida's test) lasting for 1 hour. Adrenaline excretion significantly increased during the mental load in both the groups, but no significant increase of noradrenaline was recognized. The heart rate also increased immediately after the biginning of the test, but it fell to some extent after a certain period of time. A marked physiological arrhythmia observed under the resting condition was interestingly suppressed by exposing to the mental stressor. From the change of the cardiacrhythm, it became apparent that the autonomic nervous function was more stable in the middle-aged than in the adolescent. As there was an intimaterelationship between the adrenaline excretion and the work-ing capacity, the usefulness of the urinary output of adrenaline as a parameter for mental load is discussed.
Diurnal variations of 17-ketogenic steroid, catecholamine, sodium, potassium, calcium and inorganic phosphate excretion in three-shift workers were investigated to obtain the information on the adaptability to night work, with special regard to age-difference. Catecholamine excretion rhythms, particularly adrenaline rhythm, which generally show the peak in daytime in ordinary non-shift work, were demonstrated to be adapted rapidly to night work, though not to a large extent, by the finding that the peak of excretory rhythm corresponded to the physical andmental activities in the night shift.The diurnal rhythm of 17-ketogenic steroids appeared to be flattened only on the fifth day of the night work in the middle-aged workers and the second highest peak of the rhythm was observed in the evening of the night shift day in the adolescents. Potassium rhythm was dissociated from the other electrolyte ones which were maintained in the normal rhythms evenin the night shift. The age-difference of adaptability to night work is discussed from the diurnal rhythms of 17-ketogenic steroid and adrenaline excretion.
Some changes of metabolic activities of monocytes by phagocytosing alkaline-treated or ground quartz were studied. In the experimental condition in which the TTC reducing capacity of monocytes with alkaline-treated quartz was inhibited by 50 % to control, the acid-soluble nucleotide in monocytes decreased by 40 % to control. In the lactic acid production, the succinoxidase activity and DPNH-tetrazolium reducing capacity were unaf-fected in this condition, but they dropped with further increase of dust dose, and the lactic acid production was least effected by dusts among these cellular activities. The decrease of lactic acid production was not observed until the amounts of acid-soluble nucleotide in the monocytes with alkaline-treated quartz dropped below 30 % of control. From above results it was assumed that the first step of the toxic action of alkaline-treated quartz on monocytes was not an attack to respiratory and glycolytic systems of monocytes.
It was found that the toxicity of acrylonitrile was due not only to the hydrogen cyanide liberated from it but to acrylonitrile itself. A small amount of hydrogen cyanide appeared in the blood of animals after a single injection of acrylonitrile. Although when sodium thiosulfate was injected before the acrylonitrile there was a great reduction in the hydrogen cyanide concentration in the blood and a lessening of symptoms, animals were not protected effectively from poisoning. In contrast, L-cysteine greatly reduced both the acrylonitrile and hydrogen cyanide concentration in the blood and protected the animals from poisoning. L-Cysteine formed an addition compounds with acrylonitrile in the test tube. This compound caused neither acute nor delayed symptoms when injected into animals. About 15% of the acrylonitrile given was excreted unchanged in the expired air and urine and another 15% was excreted in the urine as thiocyanate. The fate of about two-thirds of the acrylonitrile given is not yet clear. Acrylonitrile had an inhibitory effect on K+-stimulated respiration of brain cortex slices at 10-3M, whereas it had little effect on respiration of the liver at the same concentration. Acrylonitrile was judged to have a strong anesthetic effect on peripheral nerves when its effect was compared with those of various anesthetics and organic solvents. Sulfhydrile (SH) and disulfide (S-S) compounds had good therapeutic effect on acute acrylonitrile poisoning in animals, especially in rabbits which received these compounds intravenously.
It was found that acrylonitrile in acid solution reacted quantitatively with brominein ultraviolet light and developed a pink color with benzidine-pyridine reagent. The absorbance of this color obeyed Beer's law in the range of 15μg/ml. The microdeter-mination of acrylonitrile in biological materials is possible by this method. Satisfactory results were obtained on the microdetermination of cyanide in blood withchloramin-T and pyridine-pyrazolone reagent. Thiocyanate in blood was determined by Aldridge's method. Thiocyanate in urine wasfirst separated from interfering substances by anion exchange resin column chromatographyand then Aldridge's method was used.
It has been reported in the previous paper that the myelotoxicity of benzene is related to its metabolic changes. In the present paper, benzene metabolites were tested for myelotoxicity similar to that of benzene. Metabolites were administered to seven-week-old, 130 g male Donryu rats subcutaneously on the back daily. Doses of metabolites were determined by using the results of Parke's experiment. Criteria used for the evaluation were body weight, erythrocyte count, leucocyte count, thrombocyte count, and hemoglobin content of the blood taken from the tail. Reversal experiment was applied to the present studies in three sections, each for seven days, to eliminate the time factor. Phenol (0.20 g/kg) caused leucocytosis; hydroquinone (0.05 g/kg), decrease of body weight; pyrocatechol (0.03 g/kg), erythropenia and leucopenia; hydroxyhydroquinone (0.005 g/kg), t-t muconic acid (0.013 g/kg), and D, L-phenylmercapturic acid (0.01 g/kg), no changes. Conjugated phenol was tested at the same time. Potassium phenylsulfate (0.50 g/kg) caused an increase in body weight and leucocytosis. From the above results, the likely cause of hemopoietic disturbance in chronic benzene poisoning is the formation of pyrocatechol via benzeneglycol.
Individual differences in susceptibility to benzene have been observed. Systematic observations, however, using one kind of animal and one method have not been previously reported. Accordingly, the individual differences in susceptibility to benzene from the viewpoint of environment will be analyzed in the present paper. First of all, the effect of ambient temperatures on susceptibility in chronic benzene poisoning was examined. Thirty male seven-week-old Donryu rats weighing 130 g and bred at 21°C were accli-matized to 32 °C, 21°C and 10°C (relative humidity 55 %) for eight days. The rats were then given subcutaneous injections of 1.0 g/kg of benzene or same dose of olive oil for twelve successive days. Every four days blood taken from the tail was examined. The body weight of the benzene injected rats showed a decrease at all temperatures. Significant leucopenia was observed at 32°C and 21°C, while no change of leucocyte count occured at 10°C. From the above results, the rats exposed to a cold temperature were felt to be mini-mally intoxicated by benzene as compared with the rats exposed to the moderate or high temperatures.
The static pressure of the air at the outlet of high volume air sampler was picked up by the transducer. The strain of thin plate of phosphorbronze stretched in the cylindrical vessel was transformed into electrical potential by the differential transformer. The strain of thin plate of phosphorbronze stretched in the cylindrical vessel was transformed into electrical potential by the differential transformer. The continuous value of the electrical potential was transformed to the digital value by the integrated circuit, and this digital pulse was counted for measuring the air volume. Additionally, the instantaneous value of the air flow can be indicated by the meter.