The effects of whole-body irradiation with lethal and sub-lethal dose (1000 and 600 R) of X-ray on the adrenal function of rats were studied by estimating corticosterone and sterol biosynthesis from ¹⁴C-acetate in vitro to assess a functional state of adrenals. At 24 hours post-irradiation, the elevated corticosterone biosynthesis was observed in the adrenals obtained from both 600 and 1000 R X-irradiated rats, while the accelerated incorporation of ¹⁴C-acetate into free sterol was noticed in 600 R irradiated adrenals but not in the 1000 R irradiated. At 48 hours after irradiation, the elevated function of 600 R irradiated adrenals was maitained, while in the 1000 R irradiated adrenals, the both corticosterone and sterol formation in vitro were observed to be depressed markedly. The relationship between lethality and adrenal function in irradiated animals was discussed.

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Measurements of chromium and manganese in the complete diet samples collected throughout Japan were made to know the normal daily intake and percentage contribution from different food-groups. More than 70 per cent of manganese is supplied by plant products, while chromium is more evenly supplied by each food-group as in the case of iron. The daily intake of manganese is 2.7 ?? 2.9 mg in adults. The ratio Mn : Cr in raw food materials on the average was found to be 21.0 (range : 5.4 ?? 63.6), while that in cooked servings was only 3.1 ?? 4.0; this may suggest the introduction of chromium in the course of cooking.

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Swelling phenomena of the liver mitochondria were investigated in rats whose whole bodies had been subjected to X-irradiation of 1000R. The rats were killed at 4.5, 6, 17, 22 and 52 hours after irradiation. The rate of swelling of the mitochondria in reaction to various agents decreased after irradiation, reaching its lowest level at 6 hours, but gradually recovering the normal level after 22 hours. Swellings of mitochondria induced by ferrous and ferric ions in a KCl-Tris-HC1 medium were accelerated by X-irradiation, reaching the maximum at 22 hours.
A large amount of lipid peroxide, measured by the degree of formation of thiobarbiturate color matter, was formed in mitochondria treated by ferrous and ferric ions. This formation showed remarkable correlation with the mitochondrial swelling. Irradiation shortened the lag period for the formation of lipid peroxide with Fe²⁺, as was also observed in the case of mitochondrial swelling.

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The rabbits subcutaneous connective tissue reaction following X-ray irradiation and inhibitary effects of several vasoconstricting agents against this reaction were studied by means of supravital staining of the stretch preparation of the subcutaneous connective tissue.
In irradiated connective tissue perivascular granulocytic emigration was observed at the beginning of the process. They increased in number till 8-12 hours, and then degenerated and were devoured by monocytes or histiocytes disappearing in 1-3 days. In addition the monocytes increased in number in 1-3 days. This tissue reaction was inhibited for 3 postirradiation hours, when the epinephrine, norepinephrine, phenylephrine, naphazoline or atropin were administered locally 5 minutes before or immediately after irradiation. Following non-local administration of the phenylephrine or naphazoline 5 minutes before or immediately after irradiation the tissue reaction was inhibited for 5 postirradiation hours. The post-irradiation treatment by phenylephrine produced less inhibitary effect as compared with pre-irradiation treatment.
As the mechanisms of this inhibitary action the antagonism to the radiation induced vasodilatation and the hypoxia caused by vasoconstriction were discussed.

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Radiation sensitivity of amino acids in aqueous solution to γ-rays was investigated by determining a rate of decomposition of amino acids on exposure to various doses of γ-irradiation. From the results the first order rate constants of the decomposition of amino acids were determined to refer the radiation sensitivities. In the aqueous solution, methionine, cystine, threonine, histidine and arginine were proved to be more radiosensitive while cysteic acid, tyrosine, alanine and proline were relatively radioresistant.
Tryptophan, cystine, methionine, phenylalanine and tyrosine were more easily decomposed in mixture than in the free solution. Among other amino acids a reciprocal protection was found in the mixture and they were less easily decomposed in mixture than in the free solution. A protective effect of tryptophan, cystine, methionine, tyrosine and phenylalanine was proposed to other amino acids which were more radioresistant, in the γ-irradiated amino acids mixture.

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Fin whales from three geographically different regions were examined for accumulated radioactive nuclides by the gamma-ray spectrometric method. The gamma-ray spectra showed prominent peaks for radioactive zinc, manganese and cesium, apart from the naturally occurring radioisotope of potassium. Concentrations of these accumulated radionuclides by tissues and by regions have been compared. Other nuclides noticed in the spectra are ruthenium-103-106, and cerium-141-144.
Specific tissues examined revealed that ⁵⁴Mn is greatly lodged in the liver and ¹³⁷Cs in the muscle. The bone showed affinity for ⁶⁵Zn and ¹³⁷Cs and less for ⁵⁴Mn. The Hokkaido bone sample for the same year (1964), however, showed exceptionally high values for ⁵⁴Mn. The Arctic fin whales showed larger accumulation of the radionuclides than the Antarctic fin whales, confirming heavier contamination of the northern hemisphere waters.

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