Kenji Uraguchi

Chronic toxicity and carcinogenicity in mice of the purified mycotoxins, luteoskyrin and cyclochlorotine*

Abstract Long-term feeding studies in mice, initiated in 1960, have been carried out on luteoskyrin and cyclochlorotine, obtained in purified form from Penicillium islandicum Sopp, an infectant of yellowed rice. In the case of luteoskyrin, five different experiments were conducted to investigate the importance of strain, sex, dose level, frequency of dosage and type of basal grain diet on the development of acute, subacute and chronic toxicity, and especially on hepatoma induction. The results provide evidence that these two mycotoxins are responsible for the hepatotoxic and hepatocarcinogenic effects of yellowed rice. The effects of the mycotoxins differed in that necrosis was observed in the early stages with luteoskyrin, and fibrosis and cirrhosis with cyclochlorotine, but the chronic effects on the liver were similar. The tumorigenic effect of luteoskyrin on the liver was more marked in males than in females.

Absorption, distribution and excretion of luteoskyrin with special reference to the selective action on the liver

Pharmacokinetic experiments with 3H-luteoskyrin disclosed the following findings on absorption, distribution and excretion of the compound: (1) Luteoskyrin (luteo), when administered sc or po, rapidly concentrates in the liver, reaching maximum concentration about 1 day after administration. Although similar uptake curves are shown by other organs, the maximum luteo value for the liver is singularly high. The trend toward selective concentration in the liver explains the specific hepatotoxicity of luteo. (2) Most luteo administered iv quickly disappears from the blood, and a considerable amount enters the liver. The effective concentration in the liver for hepatotoxicity is low but within definite limits and is nearly the same after sc and po administration. (3) The luteo uptake varies with different organs and tissues, and the amount entering the liver shows a wide difference depending on the route of administration. This accounts for the differences seen between the iv LD50 and those values obtained after sc and po administration. (4) A slow uptake of luteo by the liver and a time lag for development of liver damage were observed; this accounts for the slow onset of toxicity of luteo. (5) Elimination of luteo gradually takes place through the liver, gastrointestinal tract and kidney, and the residual luteo is detectable in the blood, feces and urine for many days.

ber die Atemlhmung durch Tetrodotoxin

ZusammenfassungDie Atemlähmung durch das Toxin des Kugelfisches (Fugutoxin oder Tetrodotoxin) wurde untersucht. Dabei hat sich ergeben, daß das Toxin eine lähmende Wirkung sowohl auf das Atemzentrum als auch auf die neuromuskulären Synapsen hat, und daß die periphere Lähmung zuerst auftritt. Die zentrale Lähmung ist durch atemzentrumserregende Mittel aufzuheben. Die Zwerchfell-Lähmung dagegen ist sehr stark und nach Guadinin nur für kurze Zeit reversibel.Der Mechanismus der Lähmung und die Möglichkeiten der Behandlung bei einer Intoxikation durch dieses Toxin wurden diskutiert.Die Atemlahmung durch das Toxin des Kugelfisches (Fugutoxin oder Tetrodotoxin) wurde untersucht. Dabei hat sich ergeben, das das Toxin eine lahmende Wirkung sowohl auf das Atemzentrum als auch auf die neuromuskularen Synapsen hat, und das die periphere Lahmung zuerst auftritt. Die zentrale Lahmung ist durch atemzentrumserregende Mittel aufzuheben. Die Zwerchfell-Lahmung dagegen ist sehr stark und nach Guadinin nur fur kurze Zeit reversibel.

PYROGEN-PRODUCING MOLDS AND OTHER MICROBES EXISTING IN GLUCOSE-POWDER

Up to the earlier period of the war, undesirable reactions such as fever, chills, headache, general lassitude or fluctuation of white cell count following the intravenous injection of hypertonic or isotonic glucose-solutions were not so frequently witnessed. Consequently, these clinical reactions hardly presented any problem from the practical standpoint. Towards the end of the war, many commercial products of low quality were in wide circulation, some of which were revealed to be of substandard qualifications according to bacteriological or other routine investigative tests described in existing pharmacopoeia (J.P.V.). Thus we concede the fact that the flooding of those evidently inferior products in postwar markets is without doubt a factor which made worse the undesirable conditions of the therapeutic solution of glucose. Yet we could not ignore the fact that the officinal products which were apparently perfect and actually made to comform to the pharmacopoeial requirements occasionally yielded febrile reactions. As our animal, chemical and bacteriological examinations will show in detail in the next report, a high percentage of these apparently normal products in question contained pyrogens, it was detected, and we were convinced of the great role of “ pyrogens ” as the cause of thermal reactions in postwar Japan. Apart from the Billroths experiment in 1865 as to the cause of febrile reaction due to the intravenous injection of distilled water, experiments by Wechselmann(1), Hort and Penfold(2)in 1911, Seibert(3)in 1923, Bourne and Seibert(4)in 1925, Rademaker(5) in 1930 and Co Tui and Schrift(6) in 1942 have disclosed the fact that some kinds of bacteria could produce pyrogenetic substances, the chemical and biological properties of which became clear to some extent through their efforts along with the recent research of Robinson and Flusser(7) in 1944. Co Tui and Schrift(6) have suggested the probability of pyrogenetic reaction due to mold contamination, but Wylie and Todd(8) in 1948 reported that only bacteria were capable of producing pyrogens. Until after our preliminary report(9) on pyrogen-producing molds in 1948 no scientific news was available as for pyrogens and molds. Of late it was a great joy to know about above mentioned researches by American and English scholars and especially the report on pyrogen-producing molds by Harkness, Loving and Hodges(10) in 1950. As our through bacteriological examinations failed to detect directly any microbe in most of the pyrogenous glucose-solution sealed in ampullae, we have been left in the dark as to whether the pyrogan which was found in the solutions in ampullae has any causal dependence to microbes or not. This is the reason why we have decided to concentrate on glucose powders as the second step in our present research. Several years ago we successfully isolated a certain pyrogenous mold at our pharmacological institute but lost it when Professor Miyakes mycological laboratory was bombed in 1944. But, the memory of this first discovery revived our hopes in the postwar period and hence, in the present attempt to detect pyrogens and their origin, our main attention was naturally turned to molds rather than bacteria.

Experimental examination on the level of body temperature, its variability in normal rabbits, and the role of the thermal environment

Rectal temperatures of 705 rabbits were measured seven times a day under ordinary conditions. 4935 measurements obtained during three years and four months were analyzed with special reference to the environmental temperature ranging from 4°C to 31°C. The average body temperature was found 39°.40C, standard deviation being 0°.29C with normal frequency distribution. A normal level of body temperature of rabbits, in group averages, was proved to change with a certain correlation to its thermal surroundings. Daily variations, the lowest at noon and the highest in the evening throughout a year, formed a V-shaped curve and the span of the diurnal rhythm changed, with its thermal surroundings, indicating a highly unstable state of body, temperature in severe seasons. This disturbance was easily evoked in winter than in summer. A small fraction (7.6 %) of the whole data went beyond the stipulated limits (38°.9C to 39°.8C in J.P. and U.S.P.) and further analyses represented role of various external temperatures upon rabbits each temperature of the environment had its own significance in affecting the physiology of the animal. At a room temperature ranging between 17°, 28°C and 24°, 25°C, a thermal mechanism of. rabbit was most free from any restrictive influence from the outside. It was convinced that the stability of body temperature is retained on a practically constant level throughout the whole extent of this optimum range of the environmental temperature, i.e. 21°±4°C.