This review deals with the reducing ability of a dioxin-like toxic compound, coplanar polychlorinated biphenyl, 3,3′,4,4′,5-pentachlorobiphenyl (PCB126) in protein levels of rat liver aldolase B, carbonic anhydrase III, class I alcohol dehydrogenase (ADH), glucose regulated protein 78 (GRP78), GRP94, calreticulin, and calnexin as well as the inducing ability in hepatic cytosolic 54 K protein (tentative selenium binding protein/acetaminophen binding protein homologue), heat shock protein 70 (HSP70) and HSP90. These data could provide new aspects of dioxin's toxicity via marked changes in the levels of proteins with important functions.
A total of 112 male albino rats (Rattus norvegicus) were divided into seven groups and exposed to lead acetate trihydrate (0, 0.125, 0.25, 0.5, 1.0, 2.0 and 4 per cent for 1 to 8 months) in drinking water to investigate possible histochemical changes of nine renal dehydrogenases due to lead intoxication. A marked increase in the activity of lactate-, glucose-6-phosphate-, α-glycerophosphate-, reduced nicotinamide adenine dinucleotide (NAD)- and reduced nicotinamide adenine dinucleotide phosphate (NADP) dehydrogenase was observed while significant reduction was recorded in the activity of succinate-, malate-, isocitrate- and glutamate dehydrogenase. Changes in the activity of renal dehydrogenases were seen mainly in the pars recta and to a lesser extent in the pars convoluta and the ascending thick segment of the loop of Henle while the other medullary portions of the renal tubule were less affected. These histochemical findings led us to conclude that such changes in the renal dehydrogenases activities were due to chronic lead exposure and could be an adaptation to the metabolic, structural and functional alterations in the organelles of the renal cells especially the mitochondria.
Quinoline is a chemical with potential pharmaceutical components, such as antimalaria, antiulcer, and antibiotic agents. Quinoline is metabolized by CYP2A6, whose activity is generally shown by coumarin 7-hydroxylation, and the principal product is the 5,6-epoxide of quinoline. We found coumarin 7-hydroxylase activity in bovine liver microsomes and studied the interaction of quinoline and some quinoline derivatives with coumarin 7-hydroxylase activity by fluorometry. Quinoline inhibited coumarin metabolism, and the apparent Vmax value decreased to 0.39 nmol/min/nmol cytochrome P-450 (CYP) in the presence of quinoline from the value (Vmax = 0.63 nmol/min/nmol CYP) in the absence of quinoline. 5-fluoroquinoline (5FQ), 6-fluoroquinoline (6FQ) and 8-fluoroquinoline (8FQ) showed stronger inhibition than quinoline, whereas 3-fluoroquinoline (3FQ) showed weaker inhibition (apparent Vmax was 0.59 nmol/min/nmol CYP). Almost the same inhibition pattern of fluoroquinolines were found in assays of cDNA-expressed human CYP2A6. The results suggest that bovine CYP2A enzymes (s) as well as human CYP2A6 can interact strongly with monofluoroquinolines such as 5-, 6-, and 8-FQ, but weakly with 3-FQ.
Removal efficiency of monochloramine by rice bran was investigated over the range of pH 3-12. The removal rate of residual chlorine by rice bran was similar to activated carbon. Monochloramine was successfully removed with an average removal efficiency of 95% after 90 min when rice bran was applied to chlorinated sewage effluents that contained 0.22-0.46 mg/l monochloramine. The removal of monochloramine by rice bran was attributed to its decomposition by direct reaction with rice bran. Here, we report the findings of the efficiency of rice bran removal of monochloramine using the batch system in laboratory tests, and describe elucidation of the mechanism of its removal.
Phagocytic abilities between casein-induced Sprague-Dawley (SD) rat macrophage and kidney macrophage of fish were compared. First of all, latex bead phagocytosis abilities of macrophages from rat and fish by the same water sample were compared. In vitro exposure of the water samples to the induced SD rat macrophages for 4 hr at concentrations ranging from 10 × to 80 × of the water sample reduced the latex bead phagocytosis of the macrophages with concentration dependency. This result was similar with that of the head kidney macrophages from Cyprinus carpio and Carassius auratus. The most important advantage of using rat macrophage is its availability, because it is very hard to catch resident fishes in highly polluted rivers, and it is almost impossible to determine the extent of biological crisis in the river. These critical difficulties of previous monitoring systems could be solved by the application of casein-induced SD rat macrophages. With the above result, rat macrophage was used to investigate the acute toxicity of polluted water samples and compare pollution levels of the Kumho, Kum and Mankyung Rivers and Miho Creek in the southern part of Korea. Finally, it was confirmed that the in vitro monitoring system for exposure of SD rat macrophage to polluted water samples was available for environmental monitoring purposes.
Previously, we have reported that interleukin-6 (IL-6) administration reduces hepatic injury caused by carbon tetrachloride (CCl4) and induces the production of antioxidant proteins, manganese superoxide dismutase and metallothionein. In the present study, we examined whether IL-6 was induced endogenously by CCl4 administration in rats, and examined the relationship between the levels of IL-6 production and hepatic injury. Plasma samples were periodically collected after s.c. administration of 5 ml/kg of CCl4 (50%, v/v, in corn oil). IL-6 was significantly produced at 1.5 hr after administration, peaked at 8 hr and gradually decreased thereafter. The activities of hepatic marker enzymes, alanine aminotransferase (ALT) and sorbitol dehydrogenase (SDH) in plasma, gradually increased and peaked at 48 hr. As the ratio of the amount of corn oil to that of carbon tetrachloride was increased in the range of 1 : 0 to 1 : 8 (v/v), IL-6 induction was decreased, while ALT and SDH activities were augmented. When rats were treated with a pharmacological dose of dexamethasone (1 mg/kg), IL-6 production was decreased, but ALT and SDH activities were augmented. IL-6 expression immediately after CCl4 administration is suggested to play some significant role in reducing hepatic injury. These findings should be thoroughly considered when the hepatic injury model is developed based on the s.c. administration of CCl4.
The elevation of cellular glutathione (GSH) level induced by low concentrations of an nitric oxide (NO)-donor, sodium nitroprusside (SNP), and its effect on oxidant-induced cell injury were examined in RAW264.7 cells. The cellular GSH level increased 6 hr after exposure of the cells to SNP at low concentrations ranging from 0.1 to 0.5 mM, and the elevation followed the induction of mRNA coding for γ-glutamylcysteine synthetase, the rate-limiting enzyme of the de novo glutathione synthesis pathway. Pre-treatment of cells with low concentration of SNP (less than 0.25 mM) at 12 hr prior to exposure to menadione (MEND), an superoxide anion (O2-)-donor, significantly suppressed the cell injury induced by MEND alone. Simultaneous treatment with a higher concentration of SNP (1.0 mM or more) also blunted the MEND-induced cell injury. Low and high doses of NO both seem to show a preventive effect against oxidant injury: NO may protect against oxidant injury by up-regulating GSH synthesis at low concentrations, while at high concentrations it may directly react with radical oxygen species (ROS), thus acting as a free radical scavenger and blunting oxidant injury. These results suggest that modulation of the cellular glutathione metabolism through intracellular NO is a potential mechanism for enhancing the antioxidant defense of cells.
The effect of Sargassum horneri extract on bone formation in the femoral-diaphyseal and -metaphyseal tissue of rats in vitro was investigated. Femoral-diaphyseal and -metaphyseal tissues were cultured for 24 hr in Dulbecco's modified Eagle's medium containing either vehicle or a water-solubilized extract (10 and 25 μg/ml of medium) obtained from various marine algae (S. horneri, S. ringgoldianum Harvey, and S. yamadae Yoshida et T. Konno). Diaphyseal and metaphyseal calcium contents were significantly increased in the presence of S. horneri extract. Such an effect was not seen in the presence of S. ringgoldianum Harvey or S. yamadae Yoshida et T. Konno extract. Heat-treated S. horneri extracts (for 30 min at 80°C) did not have an anabolic effect on bone calcium content. Alkaline phosphatase activity and deoxyribonucleic acid (DNA) content in the femoral-diaphyseal and -metaphyseal tissues were significantly increased by culture with S. horneri extract (25 μg/ml of medium) for 24 hr. The effect of S. horneri extract in increasing calcium content, alkaline phosphatase activity, and DNA content in the femoral-diaphyseal and -metaphyseal tissues was completely abolished in the presence of cycloheximide (10-6 M), an inhibitor of protein synthesis. The present study demonstrates that, among marine algae which belong to Sargassum, S. horneri extract has a unique stimulatory effect on bone formation and calcification in vitro.
The effect of marine alga Sargassum horneri extracts on bone resorption in vitro was investigated. Femoral-diaphyseal and -metaphyseal tissues obtained from normal rats were cultured for 48 hr in Dulbecco's modified Eagle's medium (high glucose, 4.5%) supplemented with antibiotics and bovine serum albumin. The experimental cultures contained water-solubilized extracts (10, 25, and 50 μg/ml of medium) of S. horneri. The bone-resorbing factors parathyroid hormone (1-34) (PTH; 10-7 M) and prostaglandin E2 (PGE2; 10-5 M) caused a significant decrease in the diaphyseal and metaphyseal calcium content. The decrease in bone calcium content induced by PTH or PGE2 was completely inhibited by water-solubilized extracts (10, 25, and 50 μg/ml) of S. horneri. In addition, these extracts (25 and 50 μg/ml) completely prevented the PTH (10-7 M)- or PGE2 (10-5 M)-induced increase in medium glucose consumption and lactic acid production by bone tissues. Moreover, S. horneri extracts (10-50 μg/ml) blocked PTH (10-7 M)- increased acid phosphatase activity in the diaphyseal and metaphyseal tissues. These findings indicate that water-solubilized extracts of S. horneri have a direct inhibitory effect on bone resorption in tissue culture in vitro.
Antibody production is one of biomarkers sensitive to chemical toxicity. A simple assay system for evaluating toxic effect of chemicals on antibody production was developed using pokeweed mitogen (PWM)-induced IgM production by spleen cell cultures obtained from BALB/c mice. It was evaluated with reference immunomodulating chemicals. Cultured spleen cells significantly and day-dependently produced IgM after PWM stimulation. Test chemicals were added to the cultures simultaneousely with PWM. At 4 day-culture, medium IgM level and cell proliferation were determined by ELISA method and WST-8 method for mitochondrial dehydrogenase activity, respectively. Results showed that PWM-induced IgM production was dose-dependently suppressed by cyclosporin A, a typical immunosuppressor, with more susceptible inhibition of cell proliferation. On the contrary, it was increased by lead nitrate, an immunoenhancer, around 100 μM with little change in the cell proliferation. Moreover some estrogen-related compounds such as estradiol, ethynylestradiol, diethylstilbestrol and bisphenol A dissolved in dimethyl sulfoxide were applied to the assay system. Those below 1 μM affect neither the IgM production nor the cell proliferation in spleen cell cultures irrespective of mouse sex. Further for detecting active metabolites, the preincubation of a chemical with S9 mix was coupled with the assay system. The availability of the procedure was confirmed by inhibitory effect of cyclophosphamide after preincubation with S9 mix, which had no effect without S9 mix. Thus the newly developed in vitro IgM production system by mouse spleen cells is effective for evaluating toxic or modulating effects of chemicals on antibody production.
Boi-ogi-to (Fang-ji-huang-qi-tang, FJHQ) is a Kampo Medicine which has been clinically used in the treatment of arthritis and edema, and includes Astragali Radix, Atractylodes Lanceae Rhizoma, Glycyrrhizae Radix, Zingiberis Rhizoma and Zizyphi Fructus combined with Sinomeni Caulis et Rhizoma (SCR) in Japan, but with Stephania Radix (SR) in China as a substitute for SCR. We have previously reported that FJHQ containing SR [FJHQ(SR)] decreases high blood glucose levels and the elevated blood immunoreactive insulin level in streptozotocin-induced diabetic mice to a greater extent than FJHQ having SCR [FJHQ(SCR)]. In the present study, we show that FJHQ(SR) strongly decreases urinary glucose, sorbitol, fructose, myo-inositol and 1,5-anhydro-D-glucitol in STZ-diabetic mice; the effect was markedly stronger than that of FJHQ(SCR), indicating that FJHQ(SR) suppresses polyol pathway activity. The present data support the hypothesis that FJHQ(SR) may inhibit the development of diabetic complications.
A multi-residue screening method was developed for the determination of 18 pesticides in fresh fruits, vegetables and unpolished rice by supercritical fluid extraction (SFE), cleaned up with cartridge columns, and liquid chromatography-mass spectrometry with electrospray (LC/MS (ESI)). Comparing with our previous method, the number of fraction at purification was reduced to one fraction in order to reduce the preparation time, and detection limit and recovery value of almost pesticides were improved. The detection limits of the 18 pesticides were 0.04-148 ng/g in sample. Furthermore, in case of crops including many interfering peaks by UV detection, using a LC-MS (SIM) significantly improved the quantitative and qualitative analyses with less interfering peaks than UV detection.
Various malodorous substances generated from human feces were analyzed immediately after the use of a Western-style toilet by 50 subjects. The types and amounts of these malodorous components varied slightly between individuals, depending on the food that they had eaten and their state of health. Hydrogen sulfide was detected at concentrations of 5-26 ppb, methyl mercaptan at 2-15 ppb, ammonia at less than 100 ppb, propylaldehyde, fatty acids, and pyridine at about 10 ppb, and trimethylamine at around trace levels. When subjects had diarrhea, the amounts of fatty acids, particularly acetic acid, in feces were more than 100000-fold higher than in feces of those in normal health.
To obtain the usual value of aluminum, arsenic, cadmium, chromium, copper, iron, lead, manganese, mercury, molybdenum, nickel, selenium, silicon, tin, vanadium and zinc in the normal human body, the amounts of these 16 metals were determined in 89 male and 61 female Korean cadavers, whose ages ranged from 12 to 87 years. Inductively coupled plasma atomic emission spectrometry was used for analysis of heavy metals in 9 autopsied human organs (liver, kidney, cerebrum, heart, spleen, lung, bone, hair and nail). Distribution of arsenic, nickel, selenium, lead and vanadium in the human body were almost uniform. Cadmium, mercury, manganese, molybdenum, tin and zinc were found in large quantities in the metabolic organs, whereas the concentrations of aluminum, chromium and silicon were greatest in the tissues exposed to the exterior.
In the past a few decades, particular interest has been focused on the distribution and interaction between toxic and essential elements in animals and humans, since such interactions might have adaptive implications to environmental pollution. The current study was performed to assess the correlation of elemental concentration with age and the correlation between toxic and essential elements in Koreans. Toxic elements, such as Cd, Pb, Hg, and essential elements such as Se and Zn, were analyzed in internal organs (liver, kidney cortex, kidney medulla, heart, lung, spleen, cerebrum, testis and bone) of 162 Korean cadavers. The tissues were digested with a microwave digestion system and the 5 elements were determined by inductively coupled plasma atomic emission spectrometry. Positive correlation with age was observed in the following cases: Cd in the liver, kidney cortex, kidney medulla, heart and testis; Pb in testis and bone. The concentration of Hg, Se and Zn was not correlated with age in any of the tissues tested. A significantly high correlation between Hg and Se, Pb and Se was observed in liver, kidney cortex, kidney medulla, heart, lung, spleen, cerebrum, testis and bone. The correlation between Cd and Zn was significant in the liver, kidney cortex, kidney medulla, heart, lung, cerebrum, testis and bone. These results indicate that the distribution of toxic elements is similar to that of essential elements in all tissues.
The strain difference in the toxicity of cadmium (Cd) was examined in male rats. All rats of the Wistar-Imamichi (Wistar-IM) strain survived for 7 days after treatment with Cd at a dose of 5.0 mg/kg body weight, whereas 80% of the Wistar strain and 100% of the Sprague-Dawley and Fischer strains died. These results indicate that the Wistar-IM strain has strong resistance to Cd. Furthermore, the metallothionein (MT) contents of the liver, kidney and testis of Wistar-IM rats were compared with those of Fischer rats. The strain difference in the toxicity of Cd in rats did not appear to result from a difference in MT content, although further study is necessary to elucidate the role of MT.
The effect of carbon tetrachloride (CCl4) on adenosine 3′-monophosphate (3′-AMP) content and 3′-AMP-forming enzyme activity in rat liver was examined. The levels of 3′-AMP and the total amounts of adenosine 5′-triphosphate, adenosine 5′-diphosphate and adenosine 5′-monophosphate were decreased by treatment with CCl4. The 3′-AMP-forming enzyme activity in CCl4-treated rat liver homogenate was ca. 4-fold higher than that of control. The enzyme activity in CCl4-treated mitochondria was ca. 50% of control values. These results suggest that the increase in the 3′-AMP-forming enzyme activity in the cytosol may be, at least partly, due to the leakage of the enzyme activity from mitochondria in acute hepatitis induced by CCl4.