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Toothed-whales and dolphins have been hunted for human consumption in Japan, and their muscles (red meats) are highly contaminated with mercury (Hg). We investigated the distribution and toxicity of Hg in rats after oral administration of Hg-contaminated whale red meat marketed for human consumption in Japan. Rats were orally administered the red meat homogenate for seven consecutive days (0.5 g red meat/kg-bw/day). The red meat administered to rats contained 81microg/g of total mercury (T-Hg) and 13.4 microg/g of methyl mercury (M-Hg). This dose corresponds to the human consumption of 210 g red meat/60 kg-bw/week, exceeding by about 29 times the provisional tolerable weekly intake of M-Hg at 1.6 microg/kg-bw/week set by JECFA [JECFA, 2003. Joint FAO/WHO expert committee on food additives. 61st meeting, Rome]. Twenty-four hours after the last administration, the distribution of T-Hg in rat organs and biochemical parameters in serum were analyzed. The administration of red meat significantly elevated T-Hg concentrations in the liver, kidney, erythrocytes, cerebral cortex and medulla oblongata from the control levels but did not elevate the T-Hg concentration in serum, showing the typical distribution pattern of M-Hg, not of inorganic Hg. The administration slightly but significantly increased GTP activity and P concentration and decreased BUN concentration in serum, although no abnormalities were observed in rat body weight gain and movement during the 7 days. The occasional consumption of red meat from small cetaceans, therefore, could pose a health problem for not only pregnant women but also for the general population.

The purpose of this study using LLC-PK(1) cells and P-glycoprotein (P-gp) overexpressed LLC-PK(1) cells (LLC-GA5-COL 150 cells) was to investigate the secretory transport of cadmium (Cd) via endogenous and overexpressed P-gp, respectively. Cell monolayers cultured on permeable membranes were incubated at 37 degrees C for 60 min with 1 microM CdCl(2) from either the apical or the basolateral side. The basolateral-to-apical transport of Cd was 1.7 times higher than the apical-to-basolateral transport of Cd in LLC-GA5-COL 150 cells, while the transport from apical and basolateral sides was almost the same in LLC-PK(1) cells. Treatment with a P-gp monoclonal antibody, UIC2, significantly decreased the basolateral-to-apical transport of Cd in LLC-PK(1) and LLC-GA5-COL 150 cells, and significantly increased the apical-to-basolateral transport of Cd in both cells. The effects of UIC2 were more marked in LLC-GA5-COL 150 cells than in LLC-PK(1) cells. Furthermore, typical P-gp inhibitors such as cyclosporin A, and doxorubicin decreased the basolateral-to-apical transport of Cd slightly in LLC-PK(1) cells and significantly in LLC-GA5-COL 150 cells. These results suggest that Cd is extruded from the apical membrane of LLC-PK(1) and LLC-GA5-COL 150 cells, probably depending on the level of P-gp expression.

Cetaceans hunted coastally in Japan include several species of odontocete (dolphins, porpoises and beaked whales), and fresh and frozen red meat and blubber, as well as boiled internal organs, such as liver, lung, kidney and small intestine, are still sold for human consumption. Furthermore, red meat and blubber products originating from mysticete minke whales caught in the Antarctic and Northern Pacific are also sold for human consumption. We surveyed mercury and cadmium contamination levels in boiled liver, lung, kidney and red meat products being marketed in Japanese retail outlets. We also analyzed the DNA of these products to obtain information concerning gender and species. Total mercury (T-Hg) and methyl mercury (M-Hg) contamination levels in all the cetacean products were markedly higher in odontocete species than in mysticete species, and slightly higher in females than in males. T-Hg contamination in the organs was seen in the following order: boiled liver > boiled kidney=boiled lung > red meat. In particular, T-Hg concentrations in the boiled liver were high enough to cause acute intoxication even from a single ingestion: the mean ±SD (range) of T-Hg was 388 ± 543 (0.12–1980) μg/wet g. In contrast, although M-Hg contamination in the liver was not markedly higher than that in other organs, M-Hg contamination was in the following order: boiled liver > odontocete red meat > boiled kidney > boiled lung. The contamination levels of T-Hg and M-Hg in odontocete red meat, the most popular whale product, were 8.94 ± 13.3 and 5.44 ± 5.72 μg/wet g, respectively. These averages exceeded the provisional permitted levels of T-Hg (0.4 μg/wet g) and M-Hg (0.3 μg/wet g) in marine foods set by the Japanese Ministry of Health, Labor and Welfare by 22 and 18 times, respectively, suggesting the possibility of chronic intoxication by T-Hg and M-Hg with frequent consumption of odontocete red meat. Cadmium contamination levels in boiled liver, kidney and lung were 8.59 ± 12.0, 10.4 ± 8.6 and 1.66 ± 1.27 (μg/wet g), respectively.

Vasodilatory compounds in the weak acidic fraction of a benzene extract of diesel exhaust particles (DEP) were fractionated by column chromatography through silica gel, and the chemical structures of these compounds were analyzed using GC-MS and 1H-NMR. The compounds in DEP that cause vasodilation — 3- and 4-nitrophenol, 2-methyl-4-nitrophenol, 3-methy-4-nitrophenol, and 4-nitro-3-phenylphenol — were isolated and identified. All five of these nitrophenols had vasodilatory activities (10-4 to 10-6 M) in rat thoracic artery assays, and 4-nitro-3-phenylphenol was the most potent vasodilator among these compounds. In addition, nine other alkylnitrophenols were isolated from the benzene extract of DEP and characterized.

Cetacean products sold for human consumption in Japan originate from a wide range of whale, dolphin, and porpoise species caught off several areas of the Japan coast, Antarctic and North Pacific Oceans. We surveyed the total mercury (T-Hg) levels in red meat, the most popular cetacean products in Japan. We also analyzed the DNA of these to obtain information regarding species. According to the genetic analysis, the red meats originating from nine species of odontocete and six species of mystecete were sold in Japanese markets. T-Hg concentrations in all odontocete red meats (0.52-81.0 microg/wet g, n = 137) exceeded the provisional permitted level of T-Hg in marine foods set by the Japanese government (0.4 microg/wet g). The highest and second highest levels of T-Hg in the red meats were found in the false killer whale (81.0 microg/wet g) and striped dolphin (63.4 microg/wet g), respectively. These concentrations of T-Hg exceeded the permitted level of T-Hg by about 200 and 160 times, respectively, suggesting the possibility of chronic intoxication by methyl mercury due to frequent consumption of odontocete red meats. The T-Hg concentration levels were higher in odontocete species such as Baird's beaked whales and pilot whales caught off southern areas than those caught off northern areas, probably reflecting a higher Hg concentration in the seawater and/or their diet (squid and fish) in the southern area. On the other hand, T-Hg concentrations in all mystecete red meat samples except for one (0.01-0.54 microg/ wet g, n = 62) were below the permitted level of T-Hg, probably reflecting their lower trophic levels.

Some people living in Japan have traditionally eaten the internal organs of small cetaceans (toothed whales and dolphins), and a mixed package of boiled liver, kidney, lung, and so on is still marketed for human consumption. Recently, we reported that these organs are highly contaminated with mercury. In this study, we investigated the absorption, distribution, excretion, and biochemical parameters in serum and urine after a single oral administration of boiled whale liver containing 1980 microg/g of total mercury and 23.5 microg/g of methyl mercury to rats (0.2 g boiled liver/100 g rat). The single administration of the boiled liver resulted in marked increases of the mercury concentration in the rat kidney, urinary volume, and the urinary excretion of N-acetyl-beta-D-glucosanidase, albumin, and sodium, suggesting the renal toxicity caused by inorganic mercury. Furthermore, the administration increased lactate dehydrogenase activity and creatinine, potassium, and phosphorus concentrations in serum. About 95% of total mercury dose was excreted in feces and less than 0.05% was excreted in the urine. Thus, the absorption rate of mercury from the boiled whale liver appears to be about 5% or slightly higher. These data indicate that the human consumption of boiled whale liver may cause acute intoxication by the contaminated inorganic mercury.

We investigated whether the uptake of a specific antipsychotic agent, sulpiride, in Caco-2 cells is mediated by a carrier-mediated system. Caco-2 cell monolayers were cultured in plastic culture dishes and uptake and efflux studies were conducted. The determination of sulpiride was performed by HPLC. At 37 degrees C, sulpiride uptake in pH 6.0 was twice as much as in pH 7.4. At 4 degrees C, however, no significant difference was observed between pH 6.0 and 7.4. The uptake at 4 degrees C was markedly lower than that obtained at 37 degrees C. The subtraction of the uptake at 4 degrees C from the uptake at 37 degrees C indicated a saturable process, and the result of the Eadie-Hofstee plot analysis indicated that the uptake consists of two or more saturable components. The uptake was significantly inhibited by uncoupler, protonophore, amino acid modifying agent and proteinase. Sulpiride efflux was temperature-dependent and was significantly inhibited by uncoupler and amino acid modifying agent. These findings indicate that sulpiride uptake and efflux in Caco-2 cells are carrier-mediated. Furthermore, the uptake was significantly decreased by some substrates and inhibitors of peptide transporter, PEPT1, and organic cation transporters, OCTN1 and OCTN2, and was significantly increased by preloading with them. The uptake was also significantly increased by a typical substrate of P-glycoprotein. From these findings, we presumed that peptide transporter PEPT1 and organic cation transporters OCTN1 and OCTN2 are involved with this uptake. P-glycoprotein may also contribute to the efflux of sulpiride.

The effect of pH on the secretory transport of Cd through the intestinal brush border membrane was investigated using isolated rat intestinal brush border membrane vesicles (BBMV) and the Caco-2 intestinal epithelial cell line. BBMV equilibrated at pH 5.5 or 7.5 (pH(in)) were mixed with an experimental buffer at pH 5.5 or 7.5 (pH(out)) containing CdCl(2). The initial accumulation of Cd in BBMV incubated for 1 or 3 min at pH(in) 5.5 and pH(out) 7.5 (outwardly directed H(+)-gradient) was significantly higher than that at pH(in)=pH(out)=7.5, but the equilibrated Cd accumulation incubated for 30 min was marginally lower. Carbonylcyanide-p-trifluoromethoxyphenylhydrazone (FCCP), a protonophore, diminished the increasing effect of the H(+)-gradient on the initial Cd accumulation. Caco-2 cell monolayers cultured on permeable membranes were incubated with CdCl(2) from the basolateral medium, and the transport of Cd from the basolateral to apical medium and the accumulation of Cd in the monolayers were measured. Cd transport was increased by lowering the pH of the apical medium, and was accompanied by a decrease in the Cd accumulation. Coincubation with CdCl(2) and tetraethylammonium, a typical substrate for H(+)-antiport of the renal organic cation transporter, from the basolateral medium slightly but significantly decreased the basolateral-to-apical transport of Cd, with a concomitant increase in the Cd accumulation. These findings suggest the secretory transport of Cd through the intestinal brush border membrane not only via passive diffusion but also via H(+)-antiport of the putative organic cation transporter.

1999年, 全国6都市で販売されていた鯨肉製品61点について, 重金属 (水銀, カドミウム, 鉛) 及び有機塩素系化合物 (PCBs, DDTs, HCHs, HCB, dieldrin) の汚染実態調査を行った. ハクジラの赤身肉では水銀汚染が, ハクジラ及び北太平洋産ミンククジラの脂身にはPCB及び有機塩素系農薬の汚染が顕著にみられた. 鯨肉の多食によってこれらの汚染物質の摂取許容量を超えることも考えられるので, 食品としての安全性を再検討する必要がある.

This study was undertaken to analyze Cd uptake via the inorganic anion exchanger (HCO3-/Cl-) by LLC-PK1 cells cultured on permeable membranes. LLC-PK1 cells were incubated at 37 degrees with 1 microM CdCl2 added to the apical medium, and Cd accumulation in the cells was fractionated into a membrane-bound (non-internalized) Cd fraction and an internalized Cd fraction using ethyleneglycol-bis-(beta-aminoethylether)-N,N,N',N'-tetraace tic acid (EGTA), a chelating agent for Cd. Incubation at a lower temperature (4 degrees) significantly decreased the membrane-bound Cd fraction, and drastically decreased the internalized Cd fraction. Addition of NaHCO3 (a stimulator of Cd uptake via inorganic anion exchanger) to the apical medium significantly increased both membrane-bound and internalized Cd fractions, and this increase was greater for the internalized fraction. Pretreatment of cells with 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS), a specific inhibitor of inorganic anion exchangers, significantly decreased the internalized Cd fraction without changing the membrane-bound Cd fraction. Addition of NaHCO3 did not effect both Cd fractions in DIDS-pretreated cells. These results suggest that most of Cd binds non-specifically to the apical membrane surface and then is internalized via simple diffusion and some Cd specifically binds to the inorganic anion exchanger and is internalized in a metabolism-dependent manner.

A 63-year-old woman was admitted to a local hospital after the ingestion of 40% prothiofos preparation (Tokuthion) 370 mL. Gastric lavage was performed and cathartics, active charcoal, diuretics, atropine sulfate, and pralidoxime were administered. Serum cholinesterase activity was 1.3 IU/L (normal 200-460 IU/L). The patient's consciousness was gradually restored after 4 hours of charcoal hemoperfusion and she was discharged 5 days after admission with no sequelae.Plasma and urine prothiofos and metabolites were detected by gas chromatography-flame photometry and gas chromatography-mass spectrometry. Two despropyl metabolites were synthesized for identification and estimation.The main metabolites were identified with authentic prothiofos and methyl esters of synthesized des-S-propyl prothiofos oxon (O-2,4-dichlorophenyl O-ethyl phosphate), despropyl prothiofos oxon (O-2,4-dichlorophenyl O-ethyl phospholothiolate), and des-S-propyl prothiofos (O-2,4-dichlorophenyl O-ethyl phosphorothioate). Despropyl prothiofos (O-2,4-dichlorophenyl O-ethyl phosphorodithioate) was also identified in plasma. Large amounts of the hydrolyzed product, 2,4-dichlorophenol and its conjugate were also found. The metabolic pattern of prothiofos in humans appears to be different from that in rats.

Abstrast: Effects of Na + , Cl - , OH - and HCO 3 - , and an inorganic anion exchange inhibitor (HCO 3 - /Cl - / 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid, on Cd uptake from the apical membrane of LLC-PK 1 cells were investigated to elucidate the mechanism of Cd uptake by these cells. Furthermore, the initial uptake of Cd incubated at different temperatures was analyzed by using the Arrhenius plot to test if Cd is taken up by the cells via the carrier-mediated process. The cells were incubated with 1 μM CdC1 2 for 30 min. at 37° in phosphate buffer containing NaCI at pH 5.5 or 7.4. Cd accumulation by the cells at pH 7.4 was about 5 times higher than at pH 5.5. Replacement of NaCI in the phosphate buffer with KCI or mannitol decreased the Cd accumulation at pH 7.4 about 80%, but had no effect at pH 5.5. The addition of 2 mM NaHCO 3 to the pH 7.4 buffer containing NaCI significantly increased the Cd accumulation, and pretreatment of the cells with the inorganic anion exchange inhibitor abolished this effect of NaHCO 3 on Cd accumulation. The cells were incubated for 10 min. at different temperatures with I μM CdCl 2 in the phosphate buffer containing NaCI at pH 7.4 in the presence or absence of 2 mM NaHCO 3 or at pH 5.5 in the absence of NaHCO 3 . In all cases, the Arrhenius plots of Cd accumulation were nonlinear. The breakpoint was observed at about 30° in the Cd accumulation at pH 7.4 in the presence of NaHCO 3 , suggesting the involvement of a carrier-mediated process. This breakpoint was not as clear in the Cd accumulation at pH 7.4 in the absence of NaHCO 3 and not observed at all at pH 5.5. These findings suggested that Cd is partially taken up from the apical membrane of LLC-PK 1 cells via the inorganic anion exchanger and the uptake of Cd is more efficient at alkaline pH and in the presence of Na + , Cl - and HCO 3 .

The effects of essential metals, zinc (Zn) and copper (Cu), on cadmium (Cd) uptake were investigated in brush border membrane vesicles (BBMV) isolated from the rat renal cortex and LLC-PK1 cells. BBMV were incubated with Cd in the presence or absence of Zn or Cu, and then washed with a chelating agent, EGTA, to remove Cd bound to the outer surface of BBMV. Co-incubation with Zn or Cu decreased Cd accumulation in these BBMV in a concentration-dependent manner. Kinetic analysis of the initial accumulation of Cd suggested that Cd is taken up into rat BBMV via an unsaturable component and a saturable component (K(m) = 13.8 microM, V(max) = 1.44 nmol/mg protein/min), and co-incubation with Zn significantly increased the K(m) of the saturable component without affecting the V(max), whereas Cu significantly increased the K(m)-value and decreased the V(max)-value. Increasing the osmolarity of the incubation medium slightly decreased Cd accumulation in the absence of Zn or Cu, whereas it did not decrease Cd accumulation in the presence of these metals. These results suggest the possibility that, in addition to passive diffusion, Cd is also taken up from the renal brush border membrane via carrier-mediated mechanisms that are inhibited by Zn competitively and by Cu non-competitively. Furthermore, these results suggest that: (1) Cd binds externally and internally to BBMV, (2) little Cd is transported into the intravesicular space, and (3) both Zn and Cu decrease the binding and transport of Cd.

In this study, the transport of enoxacin (ENX) was investigated in a LLC-PK1 kidney epithelial cell line. The uptake of ENX by LLC-PK1 monolayers cultured in plastic dishes was shown to be temperature-dependent and concentration-dependent. Cimetidine and guanidine inhibited the uptake of ENX, whereas TEA and NMN did not. The basolateral to apical flux of ENX across LLC-PK1 monolayers cultured on permeable supports was about two times larger than the apical to basolateral flux. The basolateral to apical flux of ENX was remarkably inhibited by guanidine, whereas it was not inhibited by TEA, NMN and cimetidine. The apical to basolateral flux of ENX was inhibited by cimetidine and guanidine, whereas it was not inhibited by TEA and NMN.

Effects of zinc (Zn) and copper (Cu) on cadmium (Cd) accumulation were investigated in LLC-PK1 cells. Coincubation with Zn or Cu decreased Cd uptake by the cells in a concentration-dependent manner. Cd accumulation data suggested that Cd is taken up by the cells via simple diffusion and carrier-mediated transport. Zn and Cu significantly increased the Km of Cd uptake with no or little effect on the Vmax. Pretreatment of the cells with ouabain and a metabolic inhibitor (FCCP) significantly decreased Cd accumulation, and coincubation with Zn or Cu led to an additional decrease in Cd accumulation by these cells. Overall, it seems that, in addition to simple diffusion, Cd is also taken up by LLC-PK1 cells via carrier-mediated mechanisms that are competitively inhibited by Zn and Cu.

The effects of sulfhydryl compounds on the accumulation, removal and cytotoxicity of inorganic mercury (Hg) were investigated in primary cultures of rat renal cortical epithelial cells. The compounds investigated were 2, 3–dimercapto-succinic acid, 2, 3–dimercapto-1-propanol, D-penicillamine, glutathione (GSH) and L-cysteine. In the accumulation experiment, the cells were co-incubated with Hg and the above compounds for 30 min. (short-term) or 18 hr (long-term). In the removal experiment, cells incubated with Hg were further incubated with the above compounds for 30 min. In both experiments, the alleviative effect of the compounds on the cytotoxicity was estimated by the uptake of neutral red or by cell growth. 2, 3–Dimercaptosuccinic acid had the highest antidotal effects except for Hg removal. 2, 3–Dimercapto-1-propanol exerted the least antidotal effects in the short-term, as well as in the long-term experiments, 2, 3–dimercapto-1-propanol increased the Hg accumulation and the cytotoxicity despite its removal of most of the Hg. Although D-penicillamine, L-cysteine and GSH did not increase the Hg removal in the long-term experiment other antidotal effects were seen.

The interaction of ethanol (EtOH) and cyclohexanone (CHN) metabolism was studied to demonstrate the influence of alcohol beverage in cyclohexanone poisoning. Rabbits were administered CHN and EtOH separately or together, and the plasma concentration of CHN and cyclohexanol (CHL), a metabolite of CHN, and blood concentrations of EtOH were measured at various times. When CHN alone was administered orally, the time to maximum plasma concentration (Tmax) of CHN was as short as 15 min, but that of CHL was 120 min. The short Tmax of CHN was considered to be due to the first-pass effect. The plasma concentration of CHL was much greater than that of CHN. On the other hand, when the same amount of molar CHL was administered in rabbits for sake of comparison, only small amounts of CHN were detected in plasma. The interconversion between CHN and CHL at the time of equilibration tended to shift predominantly toward the formation of CHL, whose plasma concentration ratio was about 1:6 to 1:8. The coadministration of EtOH decreased the plasma concentration of CHN and increased that of CHL more than the administration of CHN alone. The blood concentration of EtOH was also decreased with the coadministration of CHN. The coadministration of EtOH with CHN demonstrated an acceleration in the metabolism of both CHN and EtOH, which may be due to an increase in the concentrations of the alcohol dehydrogenase-NADH and -NAD complexes.

The serum 4-O-methylpyridoxine (MPN) levels in a 21 months-old patient with gin-nan food poisoning were determined by HPLC. The blood of the patient was taken at 8.5 and 15.5 h after taking about 50 ginkgo albumens. After deproteinization of the serum, the supernatant was pretreated with Sep-pak C18 cartridge and was applied to HPLC. HPLC was performed with a Hibar LiChrosorb RP-18 (4.0 mm i.d. x 250 mm, 7 microns) using a fluorescence detector (wave length of excitation and fluorescence; 290 and 400 nm, respectively). The serum MPN level was determined by the absolute calibration method. The determination limit of MPN in the serum was 0.05 micrograms/ml. The serum MPN concentration was 0.09 micrograms/ml at 8.5 h after taking ginkgo seeds, and was less than the determination limit of MPN (0.05 micrograms/ml) at 15.5 h. MPN, isolated from the seed of Ginkgo biloba L., is responsible for "gin-nan food poisoning," and its cardinal symptoms are mainly tonic and/or clonic convulsions and loss of consciousness. Infants are particularly vulnerable. This method may be available for proving the gin-nan food poisoning, chemically.

In our continuing studies on estrogenic compounds in diesel exhaust particles (DEP), we have reported the systematic separation of alkyldibenzothiophenes from the estrogenic hexane fraction of DEP. In this study, another estrogenic fraction was further isolated and characterized. DEP were roughly fractionated by successive extraction with hexane, benzene, dichloromethane, methanol, 1 M ammonia and 1 M HCl. The hexane extract, which exhibited estrogenic activity, was further fractionated by column chromatography and high performance liquid chromatography (HPLC). From one of the obtained fractions that showed estrogenic activity, three alkyltrimethylbenzenes were identified by gas chromatography-mass spectrometry (GC-MS) and 1H-nuclear magnetic resonance (NMR) spectroscopy.

Small cetaceans (toothed whales odontoceti and dolphins delphinidae) have been traditionally hunted along the coast of Japan and fresh red meat and blubber, as well as boiled internal organs such as liver, kidney, lung and small intestine, are still being sold for human consumption. We surveyed mercury contamination in boiled liver, kidney and lung products marketed in Japan between 1999-2001. The average +/- S.D. of total mercury (T-Hg) was 370 +/- 525 (range: 7.60 approximately 1980, n = 26) microg/g in liver, 40.5 +/- 48.5 (7.30-95.1, n = 15) microg/g in kidney and 42.8 +/- 43.8 (2.10-79.6, n = 23) microg/g in lung. A high correlation was observed between T-Hg and selenium (Se) concentrations in these organs, supporting the formation of a Hg-Se complex. The formation of a Hg-Se complex probably contribute to the detoxification of Hg for cetaceans and allows a very large accumulation of Hg in livers. The provisional permitted level of T-Hg in marine foods set by the Japanese Ministry of Health and Welfare is 0.4 microg/ g, and the provisional permitted weekly intake (PTWI) set by WHO is 5 microg/kg bw/week. The maximal T-Hg detected in boiled liver (1,980 microg/g) exceeds the permitted level by approximately 5,000 times and the consumption of only 0.15 g of liver exceeds the PTWI of 60 kg of body weight of the consumer, suggesting the possibility of an acute intoxication by T-Hg even after a single consumption of the product.

The purpose of this study was to investigate whether cadmium (Cd) efflux across the apical membrane of cultured renal epithelial cells, LLC-PK(1) and OK, is mediated via P-glycoprotein (P-gp). These cells were preincubated for 30 min with a typical P-gp inhibitor such as verapamil, diltiazem, nifedipine, vinblastine, or cyclosporin A before the incubation with 1 microM (109)CdCl(2) for 15 min. Preincubation with each P-gp inhibitor significantly increased Cd accumulation in LLC-PK(1), and OK cells. Treatment of these cells with UIC2, a P-gp monoclonal antibody, also significantly increased Cd accumulation in these cells. Thus, the pretreatment of cells with P-gp inhibitor appears to increase Cd accumulation as a result of the inhibition of Cd efflux via P-gp. To confirm Cd efflux via P-gp, Cd accumulation in P-gp-overexpressed cells (LLC-GA5-COL150 cells) was compared with that in parental LLC-PK(1) cells. LLC-GA5-COL150 cells accumulated less Cd than did LLC-PK(1) cells, and the effects of the P-gp inhibitors and UIC2 on Cd accumulation were greater in LLC-GA5-COL150 cells. These results suggest that P-gp in LLC-PK(1) and OK cells appear to act as an efflux pump of Cd, decreasing cellular Cd accumulation.

The effects of a standardized extract of Ginkgo biloba L. leaves (EGb) and its terpene constituents, bilobalide and ginkgolides, on the activities of detoxification enzymes, i.e., glutathione S-transferases (GSTs) and DT-diaphorase, and glutathione contents, were investigated in the mouse liver. Oral treatment with EGb (100-1,000 mg/kg) and bilobalide (10-30 mg/kg) once a day for 4 days caused a dose-dependent elevation in GST activity. Ginkgolide A (30 mg/kg, for 4 days) also significantly elevated GST activity, whereas ginkgolide B and ginkgolide C at the same dose had no effects. EGb significantly increased the protein level of GST pi, and bilobalide significantly increased those of GST alpha and GST mu Moreover, EGb-treatment and bilobalide-treatment caused significant elevations in DT-diaphorase activity and in hepatic glutathione contents.

In a previous study, we focused on estrogenic activity of the hexane extract of diesel exhaust particles (DEP). The extract of hexane was first fractionated to acidic, phenolic and neutral portions according to their chemical properties, of which the neutral fraction was fractionated by column chromatography on silica gel. The chemical structures of compounds in these fractions were then analyzed. It was found that the neutral fraction of the hexane extract of DEP contains dibenzothiophene derivatives, one of which, 4,6-dimethyldibenzothiophene, possesses estrogenic activity.

In an earlier study using a recombinant yeast screen we found that a suspension of diesel exhaust particles (DEP) and some extracts of DEP are not estrogenic but possess anti-estrogenic activity. In the present study, estrogenic and anti-estrogenic activities of two types of DEP, type-1 (old type) and type-2 (new type) were compared. Whole DEP of both types were found to possess estrogenic and anti-estrogenic activities. The DEP were serially extracted with organic solvents and then with 1 M ammonia and 1 M HCl. In type-2 DEP, the ratio of dry weight of a hexane extract was higher than those of methanol and ammonia extracts, which were lower than those in type-1 DEP. In the hexane extract, estrogenic activity was found in both types of DEP. In the benzene and dichloromethane extracts, estrogenic and anti-estrogenic activities were found in both types of DEP. In the methanol extract, estrogenic activity was found in type-2 DEP, and extracts of both types decreased the activity of estrogen. Anti-estrogenic activity was found in extracts of ammonia and HCl from both types of DEP. It was found that both type-1 and type-2 DEP possess estrogenic and anti-estrogenic activities.

Profenofos and its metabolites were determined in a case of fatal poisoning. Little profenofos and large amounts of metabolites were detected by gas chromatography/flame photometric detection in the acid extracts of blood and urine after methylation with diazomethane. Four major metabolites containing phosphorus were identified with the synthesized metabolites, namely, despropylated profenofos, desethylated profenofos and des-S-propylated profenofos, respectively. 4-Bromo-2-chlorophenol (BCP), an aryl moiety of profenofos, was also determined in blood and urine with high performance liquid chromatograph (HPLC) as free or conjugated metabolites.

Estrogenic and anti-estrogenic activities of diesel exhaust particles (DEP) were evaluated using yeast cells expressing the human estrogen receptor and the responsive element regulating the expression of the receptor gene for beta-galactosidase (Routledge and Sumpter, 1996). It was found that a suspension of whole DEP suspension is not estrogenic but that this preparation possesses the ability to reduce the estrogen-dependent reporter activity. DEP were serially extracted with hexane, benzene, dichloromethane, methanol, and 1 M ammonia, and the estrogenic and anti-estrogenic activities of these preparations were determined. None of the extracts of DEP were estrogenic, but the extracts of benzene, dichloromethane and methanol possessed anti-estrogenic activity, and the activity of estrogen in the presence of hexane extract was slightly decreased. These results indicated that DEP contain heterologous compounds having anti-estrogenic activity. It is thought that those compounds in DEP can modulate the activity of estrogen, leading to the distruption of balance between estrogen and androgen. In this paper, the environmental effects of DEP in relation to the endocrine disrupting effect of organic compounds in DEP are discussed.

The purpose of this study was to investigate whether transport of cis-diamminedichloroplatinum II (cisplatin) across renal epithelial cell line OK cells is mediated by the organic cation transport system. OK cell monolayers cultured on permeable membranes were incubated with 100 microM cisplatin on the apical or basolateral side, and the cellular accumulation and the transport of cisplatin across the monolayer were measured. The accumulation from the basolateral medium and the basolateral-to-apical transport of cisplatin were higher than the accumulation from the apical medium and the apical-to-basolateral transport, respectively. The cell monolayers were incubated with different concentrations of cisplatin (0.02 approximately 3 mM) in the basolateral medium. The relationship between the cisplatin concentrations in the medium and in the cells revealed that cisplatin accumulation tended to be saturable. The basolateral-to-apical transport of cisplatin was increased when the pH of the apical medium was decreased, with a concomitant decrease in the accumulation of cisplatin. Coincubation of cisplatin with tetraethylammonium (TEA), a typical substrate for the organic cation transporter, significantly decreased the accumulation and transport of cisplatin from the basolateral medium. These results suggest that the uptake and basolateral-to-apical transport of cisplatin are mediated by not only simple diffusion but also by the organic cation transport system.

The purpose of this study was to investigate whether cadmium (Cd) efflux across the apical membrane of renal epithelial cells is mediated via a H + -antiport system, and to confirm the re-uptake of Cd from the apical membrane via an inorganic anion exchanger. LLC-PK 1 and OK cell monolayers cultured on permeable membranes were incubated with 1 μM CdCl 2 added to the basolateral medium, and the transport of Cd from the basolateral to apical medium and the accumulation of Cd in the monolayers were measured. Cd transport was increased by lowering the pH of the apical medium and was accompanied by a decrease in Cd accumulation. Coincubation with N′ -methylnicotinamide or cisplatin, which act as substrates of the H + -antiport systems, decreased Cd transport and increased Cd accumulation in a concentration-dependent manner. To confirm the re-uptake of Cd, LLC-PK 1 cell monolayers were pretreated with 4,4′-diisothiocyanostilbene-2,2′-disulfonic acid (DIDS), a specific inhibitor of an inorganic anion exchanger, before incubation with CdCl 2 . Pretreatment with DIDS significantly increased Cd transport and decreased Cd accumulation at an apical medium pH of 7.4, but not at pH 5.5. These results suggest bidirectional transport of Cd across the apical membrane of renal epithelial cells via a H + -antiport system (efflux) and an inorganic anion exchanger (influx), depending on the pH of the apical side.

Phellodendri cortex and its components, limonin and obacunone, shortened the sleeping time induced by α-chloralose and urethane (50 and 500 mg/kg respectively, intraperitoneal route) in mice.

The purpose of this study was to investigate the mechanism of inorganic mercury (Hg) uptake in LLC-PK1 cells, a renal tubular epithelial cell line, and to compare the results with those reported previously by us in rat renal cortical epithelial (RCE) cells in primary culture. The LLC-PK1 cells were cultured for 3-12 days, incubated with 1 microM HgCl2 in Hanks' balanced salt solution at 4 or 37 degrees C for 30 min, and washed with phosphate-buffered saline containing BAL to remove the cell membrane-bound Hg. The uptake of Hg was higher in nonconfluent cultures than in confluent cultures and higher at 37 than at 4 degrees C. In confluent culture (Day 8) Hg uptake at 4 degrees C was only 27% of that at 37 degrees C. The initial accumulation of Hg (5 min) from different concentrations of HgCl2 (0.5-50 microM) was linear and did not show a tendency toward saturation, suggesting that a carrier-mediated process was not involved. Pretreatment of cells with 10 microM FCCP, a metabolic inhibitor and a proton ionophore, 0.5 mm DIDS, an anion transport inhibitor, or 0.5 mM ouabain, a Na+/K+-ATPase inhibitor, resulted in 72, 60, and 57% reduction in Hg uptake, respectively. Furthermore, replacement of 137 mm NaCl in the incubation medium with 137 mM KCl or LiCl or 274 mM mannitol caused 30, 45, and 87% reduction in Hg uptake, respectively. These results suggest that in LLC-PK1 cells, as in RCE cells, Hg uptake is inversely related to cell density and is influenced by membrane fluidity, membrane potential, and HCO3-/Cl- transporter.

The uptake of the Cd-metallothionein complex (CdMT) into LLC-PK1 cells was investigated and compared with that of CdCl2. The cells were incubated at 37 degrees C for up to 45 min with 1 microM Cd, as either CdMT or CdCl2 at pH 5.5, 6.4, or 7.4. Under all the experimental conditions described below, the accumulation of Cd from CdMT was markedly lower than that from CdCl2. Cd accumulation at pH 7.4 from CdMT increased linearly with the time of incubation, whereas Cd accumulation from CdCl2 was saturable. Metabolic inhibitors, 2,4-dinitrophenol (DNP) and carbonylcyanide p-(trifluoromethoxy)-phenylhydrazone (FCCP), and incubation at low temperature significantly decreased Cd accumulation from both Cd compounds. Coincubation with 30 microM ZnCl2, an antagonist of CdCl2 uptake, slightly decreased Cd accumulation from CdMT, but it markedly decreased that from CdCl2. Cd accumulation from CdMT at pH 5.5 was significantly higher than at pH 6.4 or 7.4, whereas Cd accumulation from CdCl2 at pH 5.5 and 6.4 was significantly lower than at pH 7.4. Although Cd accumulation from CdCl2 at pH 7.4 was significantly decreased by coincubation with 100 microM cysteine or glutathione (GSH), this decrease was not observed at pH 5.5 or 6.4. A small amount of Cd was removed, by the chelating agent EGTA, from the cell membranes after incubation with CdMT at pH 6.4 and 7.4, whereas a considerable amount of Cd was removed by EGTA after incubation with CdMT at pH 5.5 and with CdCl2 at three pHs. It appears that the CdMT complex is taken up into LLC-PK1 cells partially via an energy-dependent process, and the increase in Cd accumulation at low pH is due to the liberation of Cd. High stability and molecular size of the CdMT complex explains why it is not taken up readily into LLC-PK1 cells.

Tissue distribution of dichlorvos (DDVP) was determined in a case of fatal ingestion using a rapid and simple gas chromatographic (GC) assay. Remarkable autopsy findings were congestion of the lung and kidneys and bleeding ulcer extending from the dorsum of the tongue to the upper pharynx. The serum cholinesterase activity was 2 IU/1, however, miosis was not observed. In the stomach, 250 ml of volatile fluid was found. Tissue distribution of DDVP was determined using a newly developed simple and rapid GC method. DDVP was found in the spleen and heart at higher concentrations (3340 and 815 micrograms/g, respectively), and also detected in the urine at the lowest level (4.5 micrograms/ml). The DDVP concentrations in blood, brain, lung, kidney and liver were 29, 9.7, 81, 80 and 20 micrograms/ml or g, respectively.

Effects of pH on internalization, membrane-binding and efflux of Cd were investigated in LLC-PK1 cells and these effects were compared with those of inorganic mercury (Hg). The cells cultured on monolayers were incubated for 30 min in phosphate buffer at pH 5.5, 6.4 or 7.4 containing 1 microM Cd or Hg. After the incubation, the cells were washed with phosphate buffered saline (PBS) or PBS containing chelating agent (EGTA or BAL) to remove membrane-bound Cd or Hg. The decrease in pH significantly decreased Cd concentration in the cells washed with PBS and with PBS-EGTA, and apparently increased the efflux of Cd from the cells. Similar changes were found in Hg concentration in the cells washed with PBS-BAL and Hg efflux from the cells, but these changes in Hg were less significant than those in Cd, respectively. The decrease in pH-increased Hg concentration in the cells washed with PBS, unlike that of Cd. These results suggest that a decrease in pH decreases the internalized Cd as a result of the decrease in membrane-bound Cd and the increase in Cd efflux. The decrease in pH also appears to decrease the internalized Hg by increasing Hg efflux and to increase the membrane-bound Hg.

Effects of sodium ions (Na+) and metabolic inhibitors on cadmium (Cd) uptake were investigated in LLC-PK1 cells derived from pig kidney under the nontoxic conditions of Cd. The inoculated cells became confluent on day 7 after the logarithmic growth phase. The initial uptake of Cd (1-60 microM) by the confluent cells (day 7) was assayed. The relationship between the Cd uptake at 37 degrees C and Cd concentration was nonlinear, but the relationship at 4 degrees C was linear. Subtraction of the Cd uptake at 4 degrees C from that at 37 degrees C showed a saturable uptake against the Cd concentration. By the Eadie-Hofstee analysis of saturable uptake, Km and Vmax were 24.6 microM and 164 pmol Cd/mg protein/min, respectively. The uptake of Cd by the cells was significantly decreased by ouabain and the metabolic inhibitors, and by the replacement of Na+ with potassium or choline ion in the incubation medium. These results suggest that Cd is incorporated into the confluent LLC-PK1 cells not only by simple diffusion but also by the carrier-mediated transport involved in Na(+)- and energy-dependent process(es).

The compounds in diesel exhaust particles (DEP) that are responsible for vasodilatation were isolated and characterized for the first time. From benzene extract of DEP, 2-methyl-4-nitrophenol, 3-methyl-4-nitrophenl and 4-nitrophenol were isolated, and their vasodilatation activities were confirmed. 3-methyl-4-nitrophenol caused dilatation of rat thoracic artery, and the other two nitrophenols, also showed vasodilatation activities.

Loxoprofen sodium (sodium 2[4-(2-oxocyclopentylmethyl) phenyl] dehydrate; CAS #68767-14-6) is a nonsteroidal, inflammatory drug marketed only in Japan. A case report describes its association with an acute asthmatic death with features resembling those evoked by similar drugs. The analytic methodology is reported. The blood levels of loxoprofen were in the therapeutic range. The tissue concentrations are reported.

A case of coma due to the drinking of a liquid cement for polyvinyl chloride resin, containing acetone, methyl ethyl ketone, cyclohexanone and polyvinyl chloride is described. The patient also simultaneously ingested the alcoholic beverage, sake. After gastric lavage, plasma exchanges and direct hemoperfusions, the patient recovered. The concentrations of these chemicals in plasma and urine were analyzed at various time intervals to estimate the clearance. The elimination half lives for acetone and methyl ethyl ketone were 18 hours and 10 hours, respectively. Although cyclohexanone made up the largest component in the solvents, the blood level was extremely low and a large amount of cyclohexanol, a metabolite of cyclohexanone was detected in the blood and urine. The glucuronide metabolite of cyclohexanol was also estimated after the hydrolysis with beta-glucuronidase. Since the conversion of cyclohexanone to cyclohexanol is known to be catalyzed by alcohol dehydrogenase, possible interactions between sake ingestion and cyclohexanone metabolism is proposed.

Ethyl 3,5,6-tri-O-acetyl-2-S-ethyl-1,2-dithio-α- D -mannofuranoside (5) reacted with bromine to give the very unstable glycosyl bromide 4, which with water gave a mixture of the 1-hydroxyl analogue (8) and the nonreducing α- D -(1→1)-linked disaccharide derivative 9. When the bromide 4 was treated with mercuric acetate or potassium acetate, 1,3,5,6-tetra-O-acetyl-2-S-ethyl-2-thio-α- D -mannofuranose (7) was obtained, but silver acetate in carbon tetrachloride gave 7 in admixture with its β-anomer (10). Methanol reacted with 4 to give an anomeric mixture of the glycofuranosides (11 and 12). An excess of chlorine converted the dithio derivative 5 into a 3,5,6-tri-O-acetyl-2-chloro-2-S-ethyl-2-thio- D -manno(or gluco)furanosyl chloride (13), whereas a lower proportion of chlorine appeared to give the 1-chloro analogue of 4. Treatment of the dichloro derivative 13 with methanol led to a mixture of three methyl glycosides, one (14) retaining the chlorine atom at C-2, and the other two (15 and 16) resulting from exchange of both chlorine atoms by methoxyl groups.

The toxicological effect of fluorocarbon-22 (FC-22, monochlorodifluoromethane) was studied using mice and rabbits. The following symptoms were observed during continuous inhalation in sequence as time proceeded: (a) reeling, (b) weakness of forelegs, (c) falling down, (d) flow of mucous fluid from mouth and nose, mydriasis, and lacrimation, (e) violent movement of body and extremities, and (f) cyanosis. The lethal concentration (LC50) for 30 min exposure in mice was 27.7% and the threshold concentration for death in rabbits was about 30%. Blood concentration of FC-22 increased rapidly to almost equilibrium state within 1 min and completely disappeared 1 hr after inhalation ceased. Blood concentration was in direct proportion to inhaled concentration. Concerning the concentration in the tissues after death following prolonged inhalation, the concentration in fat was markedly more than other tissues but when inhalation was short, the concentration in fat was far less than other tissues. The cause of death was thought to be respiratory insufficiency.

9-(2- S -Ethyl-2-thio- and α- D -mannofuranosyl)adenine ( 8α and 8β ) were synthesized from ethyl 3,5,6-tri- O -acetyl-2- S -ethyl-1,2-dithio-α- D -mannofuranoside ( 1 ) by bromination followed by coupling of the resultant bromide ( 2 ) with 6-benzamido-(chloromercuri)purine. The 2-chloro analogues ( 10α and 10β ) of 8α and 8β were obtained by way of a fusion reaction between 1,3,5,6-tetra- O -acetyl-2- S - ethyl-2-thio-α- D -mannofuranose ( 5 ) and 2,6-dichloropurine. Fusion of the bromide 2 with 2,4-bis(trimethylsilyloxy)pyrimidine and its 5-methyl derivative led to 1-(2- S - ethyl-2-thio-β- D -mannofuranosyl)uracil ( 16 ) and its thymine analogue ( 15 ). The action of Raney nickel led to rapid dechlorination of 10α and 10β , and all of the 2′-thio-nucleosides underwent desulfurization to give the corresponding 2′-deoxynucleosides. Sequential periodate oxidation-borohydride reduction converted the hexofuranosyl nucleosides into their pentofuranosyl analogues. Thus prepared were 9-(2-deoxy-α-and β- D - arabino -hexofuranosyl)adenine ( 11α and 11β ) and their 2-deoxy- D - threo -pentofuranosyl counterparts ( 6α and 2′-deoxy-3′-epiadenosine, 6β ), and 1-(2-deoxy- β- D - arabino -hexofuranosyl)-thymine ( 17 ) and -uracil ( 18 ) and their 2-deoxy- D - threo -pentofuranosyl counterparts (3′-epithymidine, 21 , and 2′-deoxy-3′-epiuridine, 20 ). Detailed n.m.r.-spectral correlations are described for the series, and various derivatives of the nucleosides are reported.

The composition of gases was measured in a cadaver, particularly in the stomach, using gas chromatography. High concentrations of carbon dioxide (CO2) and hydrogen (H2) and a low concentration of methane (CH4) were found. At an environmental temperature of 25 degrees C, the concentrations of CO2 and H2 were approximately 80% and 10%, respectively, at an advanced stage of putrefaction, while at an environmental temperature of 15 degrees C the concentrations were approximately 60% and 35%, respectively. These gases were not produced until the fourth day at 15 degrees C, but after that the volume of gases was greater than that produced at 25 degrees C, the cadaver becoming greatly enlarged. Oxygen (O2) in air injected into a body disappeared during putrefaction. This study revealed that H2 was the main component of inflammable gas in a dead body. The mechanisms of production of the gases are also discussed.

A spectrophotometric determination of CO-Hb content was investigated on the basis of double wavelength spectrophotometry. Absorbance differences at the two wavelengths at which O2-Hb has the same absorbance reflect only the CO-Hb component because the O2-Hb component is nulled out from the mixture of O2-Hb and CO-Hb. After measurement of absorbance difference, the measuring solution was saturated with pure CO and remeasured. CO-Hb % was calculated from the ratio of the absorbance differences. Since temperature significantly influences the spectrum of hemoglobin pigment, the wavelength pair changed with temperature. For accurate measurement, it was necessary to control temperature of diluting solution before dilution. Liberation of CO fro CO-Hb was observed at more than 80% CO-Hb, and 5% and 2% liberation from 100% CO-Hb occured at 100-fold dilution with 10 mm cuvette and 20-fold dilution with 2 mm cuvette respectively. Advantages of this method are that the standard curve or equation for calculation and accurate dilution are not necessary because the interfering component is nulled out and 100% CO-Hb of the standard sample is made with the same sample; and measurement is very rapid, taking less than 2 min.

A method for the determining the amount of carbon monoxide (CO) in blood is described. CO bound to hemoglobin is released with potassium ferricyanide into a known volume of head space of a disposable syringe. Vapor in the head space is withdrawn with a gastight microcyringe and injected into the gas chromatograph. CO dissolved in saturated blood is also measured by head space analysis to ascertain that dissolved CO is able to be removed with only one shaking of blood with nitrogen (N2). N2 put into the head space previously is used as internal standard. The advantages of this method lie in the ease and speed of operation with a simple and widely available instrument.

A toxic substance, 4-O-methylpyridoxine, responsible for "gin-nan food poisoning" was isolated from seeds of Ginkgo biloba L. (Ginkgoaceae). It is proposed that the toxic principle causes food poisoning through not only antagonizing vitamin B6 in the body but also inhibiting the formation of 4-aminobutyric acid from glutamate in the brain.

This paper describes the spectrophotometric determination of carboxyhemoglobin (CO-Hb) in blood on the basis of double wavelength spectrophotometry of absorbance difference. Absorbance measurements are made in the 500–600 nm region at a blood dilution of 100–200-fold. Blood is diluted with a solution containing Na 2 S 2 O 4 to provide two components of CO-Hb and deoxyhemoglobin (deoxy-Hb). Absorbance difference at the two wavelengths at which deoxy-Hb has the same absorbance reflects only the CO-Hb component because the opposite component is nulled out of the mixture. After measurement of the absorbance difference, the measuring solution is saturated with CO gas to make all Hb derivative CO-Hb and remeasured at the same wavelengths. The percent of CO-Hb is considered the absorbance difference ratio. Results obtained by the present method was in satisfactory agreement with gas chromatographic data in blood not containing methemoglobin (Met-Hb). Comparative experiments using the gas chromatographic method and the present method were performed with samples containing Met-Hb. However, while there is a deficiency in the gas chromatographic method when the samples contain Met-Hb, the results of the present method were in close agreement with theoretical values when samples are mixed with CO-Hb, O 2 -Hb and Met-Hb. Advantages of this method are that it is simple and accurate, standard curve or equation for calculation and accurate dilution are not necessary.

The carcinogenicity of vicia, galanga, lathyrus and lycium, which are plants used as human food or in folk medicine, and of caffeic acid and prunasin, which are plant constituents, was examined in an inbred strain of ACI rats. Fresh plant materials were dried, milled and mixed with the rat basal diet in the ratio of 16% and 33% of the total. The plant constituents, caffeic acid and prunasin, were mixed with the basal diet in the ratio of 0.5% and 0.03%, respectively. These diets were administered to rats for periods ranging upward from 180 days. Carcinogenic activity was not observed with any of the plants or plant constituents.

Distribution of lidocaine in tissue was investigated after spinal anesthesia and intravenous application in rabbits to examine aspects of forensic and clinical toxicology. Respiratory arrest occurred at 5-15 min after injection of 5 mg/kg hyper-baric lidocaine solution into the subarachnoid space followed by standing in the head down position. The minimum concentration of lidocaine in the middle part of the cervical spinal cord of the dead rabbits was 197 micrograms/g. On the other hand, maximum concentration in the same site at the critical state of almost complete respiratory arrest was 175 micrograms/g. The time at which the concentration of lidocaine reached a maximum in plasma and various tissues after subarachnoid administration was 10-15 min. The concentrations in the lumbar spinal cord, a site of administration, were 1200-1500 micrograms/g 5 min after the injection, which decreased gradually to about 180-250 micrograms/g at 60 min when paralysis of the hind legs began to recover. According to these data, the concentration of lidocaine in the spinal cord of rabbits required for neural blockade was presumed to be about 200 micrograms/g. Since the maximum concentrations of lidocaine in each tissue was already observed at 2.5 min after intravenous injection, transport of lidocaine from plasma to tissues was considered to be very rapid. Lidocaine accumulates most rapidly in the spleen and kidney, followed by the brain, lung, heart, spinal cord and plasma. The concentration in the liver was the least because of its hepatic metabolism. Distribution to adipose tissue was slower than that to other tissues, but the highest accumulation was observed at the late stage. Elimination rates of plasma and tissues other than adipose were almost the same.