Absorption, elimination, and distribution of radioactive selenium were examined after a long term repeated oral administration of sodium ⁷⁵Se-selenite (0.03mg/kg/day) in male rats. Oral administration of the compound and measurement of radioactivities in the whole body of living animals, in feces and urine just before each dosing, were continued every day for approximately 90 days, using a Packard ARMAC scintillation counter. Whole body count of ⁷⁵Se increased rapidly during the initial 10 days and thereafter continued to increase rather slowly and linearly. It was observed that radioactivity was excreted mainly via urine and a small amount in feces. After the termination of repeatad administration of sodium ⁷⁵Se-selenite for 90 days, elimination of ⁷⁵Se was rather rapid for 10 days, and later, it continued slowly and the whole body count decreased along an exponential line. Therefore, linear retention line of selenium was depicted graphically on a semilogarithmic scale. Biological half-life of absorbed labeled selenium in the whole body, calculated from this line, was 26.4 days. Biological half-life of ⁷⁵Se in each organ and tissue was also calculated as follows : sodium ⁷⁵Se-selenite (0.03mg/kg/day) solution was given to a number of rats by repeated daily administration for 15 days, and the distribution pattern was observed at 4, 22, 39 and 65 days after the termination of administration, measuring the γ-radio-activities in 17 kinds of organs and tissues with well-type scintillation counter. The values obtained for were 36 days for hair, 29.9 days, for thyroid, 26.9 days, for pituitary, all longer than the value in the whole body. By the repeated administration of sodium ⁷⁵Se-selenite for 35 and 90 days, remarkable accumulation of ⁷⁵Se was found in the epididymis, kidney, liver, and testis, but the content of ⁷⁵Se in the liver and testis decreased significantly 65 days after the termination of administration.

View full abstract

In continuation of previous studies on the subacute toxicity of sodium selenate, distribution of selenium in the tissues, time-excretion of selenium in urine and feces and biochemical examinations of serum were examined after administration of sodium selenate to rats at continuous oral dosage of 1 and 5 mg/kg/day for 30 days. It was found that excretion of selenium in urine was 2-5 times of that in feces and time-excretion patterns of selenium in urine were markedly different according to sexes. The accumulation of sodium selenate was the highest in the liver, followed by the kidney, testis, lung, and spleen, in that order, but the concentration of accumulated selenate was the highest in the kidney, followed by the liver, spleen, and pancrease, in that order. After continuous administration of sodium selenate for 30 days, rats became anemic due to decrease in the number of red blood cells, amount of hemoglobin and hematocrit value. Female rats in the groups given 5 mg/kg/day showed lower values of protein, and A/G ratio, and higher value of GPT compared with the control group. It was recognized that accumulated selenium in the liver produced subacute yellow liver atrophy due to damage of liver function.

View full abstract

A fluorometric method for the determination of sodium alkylbenzene sulfonate was investigated. The proposed method utilized the quenching effect of fluorescence of acridine orange forming a complex by reaction with the surfactant. After mixing a sample and the dye solution with stirring and allowing to stand under a definite condition, the intensity of fluorescence obtained by irradiation with a exciting light at 490 nm was measured at 525 nm by spectrofluorometer. Since the proposed method was confirmed to be better than the official method using Methylene Blue because of its simple procedure, high sensitivity, and small standard deviation, it would be available as a routing method for the determination of sodium alkylbenzene sulfonate.

View full abstract

Several halogenated bisphenols were converted into a series of dechlorinated bisphenol derivatives by ultraviolet irradiation in isopropanol under nitrogen gas. The observed rate of photodegradation was a first order reaction with respect to the bisphenols concentration, and decreased with increasing number of their chlorines. Photolysis of dichlorophene, which contains two chlorines, progressed through two consecutive steps of dechlorination, and produced 2, 2'-dihydroxydiphenylmethane via 5-chloro-2, 2'-dihydroxydiphenylmethane. Similarly, bithionol which contains four chlorines was photodegraded, and gave a series of dechlorinated derivatives, 2, 2'-dihydroxytrichlorodiphenyl sulfide, 2, 2'-dihydroxydichlorodiphenyl sulfide, and 2, 2'-dihydroxychlorodiphenyl sulfide. On the other hand, dichlorophene was degraded by irradation in aqueous alkali, but yielded little dechlorinated products.

View full abstract

Enzymic nitro-reducing system, converting parathion to aminoparathion, was demonstrated in spinach homogenate (supernatant of 2000 rpm × 3 min centrifugation) and its properties were investigated. This enzyme system was active only under anaerobic condition and markedly accelerated by the addition of NADP, G-6-P, and FAD. The activity of NADH as a hydrogen donor was about one-third of that of NADPH. Addition of FMN or riboflavin instead of FAD also activated this enzyme system. These properties as well as heat lability were very similar to those of the nitro-reductase system in mammalian liver microsomes. The optimal concentration of homogenate in the reaction medium was observed, i.e., homogenate equivalent to 50 mg of spinach per 1 ml of reaction medium showed the highest activity. The addition of heat-treated homogenate to original homogenate accelerated the activity. These facts reveal the presence of an inhibitor and an activator in the homogenate for this enzyme system.

View full abstract

Periodical and quantitative changes in the amount of metallothionein, formed by a single administration of cadmium, were examined. Male Wistar rats were given intravenous injection of ¹⁰⁹CdCl₂ solution (1 mg Cd/kg) or subcutaneous injection (3 mg Cd/kg) and, 0.5, 1, 6, and 24 hr after intravenous injection or 1, 2, 4, 8, 16, 32, and 64 days after subcutaneous injection, liver, kidney, and small intestinal mucosa supernatant (s) were fractionated by Sephadex G-75 column. (1) In the liver, a larger amount of cadmium was bound to high molecular proteins rather than as metallothionein 1 hr after the administration of ¹⁰⁹CdCl₂ but the situation was reversed after 6 hr and almost all cadmium was present as metallothionein which increased rapidly thereafter, reaching a maximum on 8 th day. Subsequently, it decreased with time and became about 1/3 after 64 days. (2) In the kidneys, almost all cadmium was present as metallothionein in the initial stages after the administration but its increase was smaller than that in the liver, though reaching a maximum on 8 th day. Subsequent decrease was extremely gradual and 4/5 of the 8-day value was present even after 64 days, being in the same level as that in the liver. (3) In the small intestinal mucosa, cadmium was bound to both metallothionein and high-molecular protein 1 hr after the administration, but most of it was present as metallothionein after 6 hr. Cadmium decreased with time thereafter.

View full abstract

Several conventional methods for spectrophotometric determination of pyridine in stack gases were examined, but they did not show a satisfying result and a new method has been established. The gas containing pyridine was absorbed in 0.1 N sulfuric acid and reacted with pyrazolone and cyanogen chloride to form a blue complex. The absorbance was measured at near 620 nm. The calibration curve followed Beer's low. Ammonia and nitrogen dioxide did not interfere but sulfur dioxide interfered the determination, which was removed by potassium hydroxide trap without loss of pyridine. The color was stable at least for 60 min and the procedure is comparatively simple.

View full abstract

An analytical method for radioactive cobalt and iron in marine organisms was developed by the use of ion exchange separation and electrodeposition. The radioactive cobalt and iron were adsorbed on an anion exchange resin and eluted, the former with 4 N HCl, and the latter with 0.6 N HCl. Each of these effluents was evaporated to dryness. The residue containing radioactive cobalt was dissolved in ammonium water containing ammonium chloride and sodium bisulfite, and radioactive cobalt was electrodeposited on a copper plate at 0.5 A/cm², in order to measure the radioactivity. The other residue containing radioactive iron was dissolved in a solution of ammonium oxalate plus citric acid, and radioactive iron was electrodeposited on a copper plate at 0.2 A/cm². The radiochemical recovery of both nuclides by this method was more than 97%. Using this method analysis of radioactive cobalt and iron in seaweed obtained at the Tsuruga coast near the atomic power plant was carried out. From the result of the measurement of radioactivities, it was found that the concentrations of radioactive cobalt and iron were lower than 2 pCi/g ash.

View full abstract