Recent studies have elucidated that a variety of metals, including heavy toxic metals as well as essential metals, regulate cellular content of heme by controlling the activities of enzymes in heme metabolic pathways. This review shows that at the first and rate-limiting stages δ-aminolevulinic acid synthetase, δ-aminolevulinic acid dehydratase at the second stage and ferrochelatase, the last enzymes in the heme biosynthetic pathway, as well as heme oxygenase, the first and rate-limiting enzyme of the heme degradation, readily respond to metals (As, Cd, Cr, Co, Au, In, Fe, Pb, Mn, Hg, Ni, Pt, Se, Ag, Sn and Zn). The consequences of the metal actions on heme synthesis and degradation arise substantial depletion of cellular content of hemoprotein, cytochrome P-450. Concomitantly, this depletion alters the activity of cytochrome P-450-dependent mixed-function oxidase. Furthermore, the effects of metals on the induction of metallothionein and on the content of glutathione are also discussed.

View full abstract

The effects of polychlorinated biphenyl (Kanechlor-400) on the functions of human erythrocyte membranes were studied, and the following results were obtained. (1) Kanechlor-400 (KC-400) inhibited Ca²⁺-ATPase activity (maximal inhibition : 72%), while non-chlorinated biphenyl failed to inhibit Ca²⁺-ATPase activity. The inhibition of Ca²⁺-ATPase activity by KC-400 was due to a change in maximal rate (V_max), but not to a change in affinity (Km) for Ca²⁺ or ATP. (2) KC-400 and biphenyl protected erythrocytes against hypotonic hemolysis, but KC-400 was a more potent stabilizer of the membrane (by at least one order of magnitude) than biphenyl. (3) KC-400 and biphenyl caused similar shape alterations in erythrocytes. Namely, these compounds induced shape changes from normal discocytes to invaginated cells and finally to spherocytes. However, the concentrations required to produce shape alterations are one order of magnitude lower for KC-400 than for biphenyl. (4) These data suggested that KC-400 penetrates into the interior of the membrane, and perturbs its structure and function. Chlorination of the aromatic rings increases not only the inhibitory action on Ca²⁺-ATPase activity, but also the anti-hemolytic and shape changing actions.

View full abstract

In order to elucidate the effect of fiber reinforced plastics (FRP) for water works on the water quality, the time course of elution of organic matters from FRP test pieces was investigated and the free available chlorine consumption by test pieces was also studied. Total organic carbon (TOC) of the water, in which test pieces were immersed, was regarded as the amount of organic matters eluted from test pieces to water. The amount eluted to distilled water was propotional to the surface area of test pieces, and entirely dependent on the water temperature. The similar tendency was observed in the amount of styrene contained in the eluted organic matters. Gel filtration of the eluate showed that the organic matter contained high molecular weight substances. The organic matter was also eluted from the test pieces which had been washed with tap water during 12 months. The chlorine had no effect on the elution profile of organic matters from test pieces. The time course of elution of styrene, however, showed a time lag in the presence of chlorine. The styrene reacted with the chlorine in water and the product was 1-phenyl-2-chloroethanol. The chlorine consumption by test pieces, however, was not able to be estimated by the amount of eluted styrene. A linear relationship existed between the decrease of chlorine and the square root of time. Its slope was propotional to the initial concentration of chlorine and the surface area of test pieces. The chlorine consumption by test pieces could be explained by the assumption that the diffusion of chlorine into the interface between test pieces and water was the rate-determining step.

View full abstract

Ethylene oxide (EO) is widely used as sterilizer for many products including medical devices which are to be brought into direct contact with body fluid. Chemical change of EO in saline was investigated in relation to its residual toxicity. EO was dissolved in saline (pH 5.8) to give the final concentration of 500 μg/ml and the solution was warmed at 40°C for various periods. Formation of various compounds from EO and their quantitative changes were studied qualitatively and quantitatively by using gas-liquid chromatography, mass spectrometry and chemical test. Changes of the amounts with time for 24 hours of ethylene chlorohydrin (ECH) and ethylene glycol (EG), which are both members of the main products from EO in saline, were as follows : amount of EG was smaller than that of ECH for the initial 7.5 hours, and it was greater than that of ECH for the remainder of the experimental period. Amount of EG increased markedly from hour 16 and reached about 140 μg/ml at hour 21, while amount of ECH reached its maximum (50 μg/ml) at hour 16 and thereafter decreased gradually. The pH of the solution rose rapidly to about 10.3 for the initial 8 hours, and thereafter kept constant. These results suggest that EG was mainly formed directly from EO through the addition of H⁺ to EO for the early period, and that EG was mainly formed from ECH through the substitution of Cl in ECH by OH under basic conditions for the later peried. Formation of the two compounds which have not been reported to be formed from EO was found after hour 8. These compounds were identified as β-hydroxyethoxy acetaldehyde and its tautomer, monohydroxy dioxan. They seem to be formed by oxidation of diethylene glycol, which was produced by the addition of EO to EG, with air. As oxidation products of EG, glyoxal and glycolaldehyde monomer were detected after hour 8, and then glyoxylic acid, and glycolic acid were detected in a week. Acetaldehyde, rearrangement product of EO, was also detected.

View full abstract

Benzalkonium chloride used as detergents and disinfectants was readily analyzed by gas chromatography (GC) of their reduction products obtained by their treatment with NaBH₄ and NiCl₂. The reduction products of benzalkonium chloride (alkyldimethylbenzylammonium chloride) were identified as alkyldimethylamines (I-VI) by GC-mass spectrometry. In the reduction, the benzyl groups of alkyldimethylbenzylammonium chloride was eliminated as toluene. The procedure is applicable for characterizing the distribution of long chain alkyl groups in benzalkonium chloride, and suited for the assay of 10-100 μg/ml aqueous solution of benzalkonium chloride (mainly consisting of the n-C₁₂H₂₅, n-C₁₄H₂₉ and n-C₁₆H₃₃ homolog components : Zephiran). Furthermore, the procedure is very useful for routine analysis of benzalkonium chloride since the reduction takes place smoothly by the use of NaBH₄ and NiCl₂ which are relatively safe to handle and inexpensive, instead of a complicated apparatus and expensive catalyst in catalytic hydrogenation.

View full abstract

In order to investigate the metabolism of sodium propionate in rats, respiratory expiration, urinary and fecal excretion and tissue distribution were studied after single oral administration of [2-¹⁴C] sodium propionate. The expiration of ¹⁴CO₂ was rapid, and a half of the radioactivity administered was expired within 4 hours. The amount of radioactivity expired during three days was 77 per cent. About 7 per cent of the radioactivity administered was excreted in feces and urine during three days, of which unchanged ¹⁴C-propionate accounted for only a trace. Relatively high levels of radioactivity were observed in skin, liver, intestine and adipose tissue at three days after administration. The amounts of radioactivity distributed to these tissues were 3.9, 1.1, 0.9 and 0.7 per cent, respectively. There were no marked differences among the concentrations of radioactivity in all examined organs, including the above-mentioned tissues. It was found that about 10 per cent of the radioactivity in the liver at three days after administration was incorporated into glycogen. The radioactivity found in the lipid fraction amounted to 29 and 80 per cent of the total radioactivity in skin and adipose tissue, respectively.

View full abstract

Disappearance of free available chlorine in water during storage in the FRP (fiber reinforced plastics) tank was investigated. It was considered that the disappearance of free available chlorine in the water consists of the following factors. 1) the vaporization of free available chlorine from the water surface 2) the chlorine consumption caused by unknown components in water supply 3) the chlorine consumption caused by FRP 4) the disappearance of free available chlorine by certain reactions with sunbeams passing through the tank The third and the fourth factors could be negligible compared with the other factors. The following equation was derived in order to account for the disappearance of free available chlorine in water during storage in the FRP tank. dC_F/dt=-αC_F-K_eS (1/V) where, C_F is the concentration of free available chlorine in the tank water. α is the apparent rate constant for the chlorine consumption by components in water supply. K_e is the apparent rate coefficient for vaporization. S is the air-water interfacial area. V is the volume of water. This equation may be applied for the disappearance of free available chlorine in the tank water, when the water was continuously pumped from the tank at a constant flow rate.

View full abstract

Changes in the quality of domestic tap water during contact with pure copper, zinc, lead and iron as model materials were investigated by chemical and instrumental analyses. When neutral water containing 1-8 ppm free chlorine and no buffer reagent was placed in contact with pure these pieces at 20°C, the concentration of free-Cl in the water decreased rapidly with time, and pH of the water was lowered in contact with Cu and Fe pieces, but rose in contact with Zn and Pb pieces. These metals dissolved in the water were easily oxidized with free-Cl to form large precipitates of hydroxides/oxides of these metals. An increase in the metal-concentrations and a decrease in the free-Cl-concentrations in the water were suppressed by the formation of protective film on the Pb pieces when the water was placed for a long time in contact with Pb pieces. However, this suppression was not observed for Cu, Zn and Fe pieces. Results of experiment conducted in the presence of Palitzsch buffer reagent (pH of 7.0) showed that the greatest reduction in the concentration of free-Cl and the highest metal-concentration in the water were observed for Zn pieces, while the smallest and lowest values were obtained for Cu pieces. In addition, it was found that the dissolved metals were present in small precipitates (may be hydroxides and oxides) or metal ions in the water.

View full abstract

Microdetermination of manganese in red cells by flameless atomic absorption spectrometry (F. A. A. S.) was studied by use of rabbit blood. In a centrifuge tube (vol. 10 ml), 0.5 ml of red cells was digested with nitric acid and hydrogen peroxide on the boiling water bath. In order to avoid contamination from outside, a glass tube bended at right angles was put on the container and the wet digestion was carried out in the shielded room. The digested solution was dried on wet NaOH under reduced pressure in a desiccator. After dissolving the dried residue in 1.5 ml of 4 N HCl, iron was removed by twice extraction with 0.5 ml of tributyl phosphate. One ml of the aqueous phase and 0.5 ml of 0.01 % sulfosalicylic acid were put in another tube, and pH of the mixture was adjusted to about 10 with NH₄OH indicated with phenolphthalein. After 0.1 ml of 5% hydroxylamine hydrochloride was added, manganese was extracted with 1 ml of 0.02 % dithizone-0.01 M ortho-phenanthroline chloroform soln. as ternary complex. Twenty μl of organic phase was submitted to measurement by F.A.A.S. Operating conditions were as follows : dry, 5A-20s ; ash, 70A-30s ; atomize, 220A-5s. Under these conditions, the calibration curve for standard manganese solutions was linear in the range of 0-50 ppb. Determination of manganese in red cells could be performed by absolute calibration method. Manganese contents in red cells of three rabbits were 18.1±0.7, 82.7±1.2 and 64.3±6.8 ppb, respectively.

View full abstract

Sympathomimetic amines, amphetamine and methamphetamine, were determined as trifluoroacetyl derivatives by gas chromatography (GC) equipped with a flame-thermionic detector (FTD). Resolution of these derivatives was carried out in a glass column (3 mm×1 m), packed with 1.5% SE-30 on Chromosorb W (AW-DMCS) at 110°C, with helium at a flow rate 50 ml/min. Detection limit of these amines was 0.1 ng. In a case of the autopsy samples from 4.5 month-postmortem suspected the intoxication of methamphetamine, we could detect the amine by FTD-GC, and the content was calculated to be 12.5 μg per g wet weight liver.

View full abstract

Sympathomimetic amines, methamphetamine and amphetamine, in gauze used for wiping the face and neck of habitual suspects of methamphetamine were determined by mass fragmentography as heptafluorobutyryl derivatives. Detection limit of these amines was 5 pg. By using this analytical method, we could detect both methamphetamine and amphetamine in gauze even after seven days from the last injection (30 mg, i.v.)

View full abstract