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Dick D, Ng KM, Sauder DN, Chu I. In vitro and in vivo percutaneous absorption of 14C-chloroform in humans. Hum Exp Toxicol 1995; 14:260-5. [PMID: 7779456 DOI: 10.1177/096032719501400305] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Chloroform has been found in potable water and there is concern that significant dermal absorption may arise from daily bathing and other activities. The present study examines percutaneous absorption of 14C-chloroform in vivo using human volunteers and in vitro using fresh, excised human skin in a flow-through diffusion cell system. Fifty microlitre doses of either 1000 micrograms ml-1 chloroform in distilled water, (16.1 micrograms cm-2) or 5000 micrograms ml-1 of chloroform in ethanol, (80.6 micrograms cm-1) were applied to the forearm of volunteers with exhaled air and urine being collected for analysis. Single doses of either 0.4 microgram ml-1 chloroform in distilled water (low dose, 0.62 microgram cm-2, 1.0 ml dosed) or 900 micrograms ml-1 chloroform in distilled water (high dose, 70.3 micrograms cm-2, 50 microliters dosed) were applied to discs of the excised abdominal skin placed in flow-through diffusion cells and perfused with Hepes buffered Hank's balanced salt solution, with a wash at 4 h. In vivo absorption was 7.8 +/- 1.4% (water as vehicle) and 1.6 +/- 0.3% (ethanol as vehicle). Of the dose absorbed in vivo, more than 95% was excreted via the lungs (over 88% of which was CO2), and the maximum pulmonary excretion occurred between 15 min and 2 h after dosing. The percentage of dose absorbed in vitro (skin+perfusate) was 5.6 +/- 2.7% (low dose) and 7.1 +/- 1.4% (high dose). The above data demonstrate that a significant amount of the dissolved chloroform penetrates through the human skin, and that a higher percentage of the applied dose was absorbed using water as vehicle.(ABSTRACT TRUNCATED AT 250 WORDS)
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Moody RP, Nadeau B, Chu I. In vivo and in vitro dermal absorption of benzo[a]pyrene in rat, guinea pig, human and tissue-cultured skin. J Dermatol Sci 1995; 9:48-58. [PMID: 7727354 DOI: 10.1016/0923-1811(94)00356-j] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Cross-species in vitro dermal absorption tests were conducted with 14C-labelled benzo[a]pyrene dissolved in acetone and applied to dermatomed skin (0.5 mm thickness) at comparable dose rates (8-13 micrograms/cm2). Skin absorption was determined using the Bronaugh in vitro flow-through procedure. The percentage (%) dermal absorption included the % 14C-activity detected persisting in the skin added to that detected in the receiver solution. Listed in decreasing order, total % in vitro dermal absorption obtained by 48 h postexposure was: 95 +/- 9.6% (rat), 51 +/- 3.0% (hairless guinea pig), 43 +/- 8.7% (human; 50-year-old), 34 +/- 12.4% (Testskin) and 23 +/- 5.3% (human; 32-year-old). Comparative in vivo studies demonstrated urinary recovery of 8 +/- 1.8% and 25 +/- 5.0% for rats (dose rate: 6 micrograms/cm2) and hairless guinea pigs (dose rate: 9 micrograms/cm2), respectively. Total faecal recovery was 61 +/- 6.0% and 43 +/- 6.1% for rats and guinea pigs, respectively. Necropsies conducted at 14 days postexposure demonstrated total 14C-activity tissue recoveries of 0.5 +/- 0.13% and 0.6 +/- 0.17% in rats and guinea pigs, respectively. Including the 14C-activity extracted from the skin removed from the dose site at 14 days postexposure, the total % in vivo dermal absorbtion was 70 +/- 7.6% and 68 +/- 9.3% for rats and guinea pigs, respectively. In summary, the in vitro data was consistent with the in vivo data in demonstrating that 14C-benzo[a]pyrene was well absorbed through skin.
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Poon R, Chu I, Lecavalier P, Bergman A, Villeneuve DC. Urinary ascorbic acid--HPLC determination and application as a noninvasive biomarker of hepatic response. JOURNAL OF BIOCHEMICAL TOXICOLOGY 1994; 9:297-304. [PMID: 7891365 DOI: 10.1002/jbt.2570090604] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A high-performance liquid chromatograph (HPLC) procedure has been developed for the determination of rat urinary ascorbic acid, a major metabolite of the hepatic glucuronic acid pathway. The presence of EDTA and HCl effectively inhibited degradation of ascorbic acid during the collection of urine specimens. The reliability of the procedure was demonstrated by its high recovery (90%), specificity (characteristic absorption maximum and discrimination from isoascorbic acid), and reproducibility (2-3% coefficient of variation). The usefulness of this assay as an indicator of hepatic response was demonstrated in preliminary experiments where increases in urinary ascorbic acid excretion were detected in male rats treated with PCB 126 (3,3',4,4',5-pentachlorobiphenyl) or PCB 105 (2,3,3',4,4'-pentachlorobiphenyl). The HPLC measurement also showed that the two PCB congeners differed markedly in their potency in stimulating urinary ascorbic acid excretion. For example, 10 micrograms/kg bw/day of PCB 126 was sufficient to cause a fourfold increase in urinary ascorbic excretion while 5000 micrograms/kg bw/day of PCB 105 was required for a sevenfold increase. In response to the administration of PCB 105 or PCB 126, urinary ascorbic acid appeared to increase to the same extent as increases in hepatic ethoxyresorufin O-deethylase (EROD) and UDP-glucuronosyltransferase (UGT) activities, and to a much higher extent than changes in liver weight and hematological and serum clinical chemical parameters. The sensitivity and specificity, the ease in obtaining timed specimens, and the noninvasive nature make this assay a useful biomarker of hepatic response in dose-finding and various acute and chronic studies.
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Moody R, Nadeau B, Chu I. In vitro dermal absorption of pesticides: VI. In vivo and in vitro comparison of the organochlorine insecticide DDT in rat, guinea pig, pig, human and tissue-cultured skin. Toxicol In Vitro 1994; 8:1225-32. [DOI: 10.1016/0887-2333(94)90113-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/1993] [Revised: 04/06/1994] [Indexed: 11/29/2022]
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Håkansson H, Manzoor E, Trossvik C, Ahlborg UG, Chu I, Villenueve D. Effect on tissue vitamin A levels in the rat following subchronic exposure to four individual PCB congeners (IUPAC 77, 118, 126, and 153). CHEMOSPHERE 1994; 29:2309-2313. [PMID: 7850379 DOI: 10.1016/0045-6535(94)90399-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The present study was carried out to investigate the effect on tissue vitamin A levels in rats exposed to 3,3',4,4'-tetraCB (CB-77), 2,3',4,4',5-pentaCB (CB-118), 3,3',4,4',5-pentaCB (CB-126), and 2,2',4,4',5,5'-hexaCB (CB-153). The obtained results show that hepatic vitamin A levels are reduced both in male and female rats following dietary exposure to individual PCB congeners for 13 weeks. However, there are pronounced potency differences between congeners. Compared to TCDD, the hepatic vitamin A reducing potencies of CB-126, CB-77 and CB-153, are 0.05, 0.0001 and 0.00001, respectively, in male rats. Compared to male rats, female rats are equally sensitive to hepatic vitamin A reduction both by TCDD and dioxinlike CBs. Effects on renal and pulmonary vitamin A levels vary between CBs and between sexes.
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Lecavalier PR, Chu I, Villeneuve D, Valli VE. Combined effects of mercury and hexachlorobenzene in the rat. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART. B, PESTICIDES, FOOD CONTAMINANTS, AND AGRICULTURAL WASTES 1994; 29:951-961. [PMID: 8089432 DOI: 10.1080/03601239409372911] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The objective of the present study was to assess the potential interactive effects of two Great Lakes chemical contaminants, hexachlorobenzene (HCB) and mercury (HgCl2). Groups of 10 female Sprague-Dawley rats were administered by gavage single doses of HCB (400, 600 mg/kg b.w. in corn oil), HgCl2 (10.0, 12.5 mg/kg b.w. aqueous) or combinations of both followed by observation for clinical signs of toxicity for 14 days. Five animals from treatment groups died before the termination of the study; one animal each in 600 mg HCB, 400 mg HCB + 10 mg HgCl2, and 600 mg HCB + 10 mg HgCl2, and two animals in 600 mg HCB + 12.5 mg HgCl2. The surviving animals were necropsied at the termination of the study, and hematological, clinical chemistry, histopathological and tissue residue analyses were performed. Relative liver weights were increased in both low and high dose groups of HCB but not in animals treated with HgCl2 alone. Co-administration of HgCl2 did not alter the HCB effects on the liver weight of the animals. Serum cholesterol levels were increased in all the groups receiving HCB but not HgCl2. No interactive effects on other serum parameters were seen in animals administered with both chemicals. Mild to moderate morphological changes occurred in the liver, thyroid, thymus, ovary and bone marrow of rats exposed to HCB or HCB+HgCl2, and in the kidney of HgCl2 or HgCl2+HCB treated animals. More severe histological changes occurred in the groups receiving both chemicals. The histological effects appeared to be additive. It was concluded that co-administration with HCB and HgCl2 resulted in additive effects in some of the endpoints measured but no synergism or antagonism was observed.
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Poon R, Chu I, Villeneuve DC, Valli VE. Short-term toxicity of bitumen upgrading products in the rat following repeated dermal exposure. FUNDAMENTAL AND APPLIED TOXICOLOGY : OFFICIAL JOURNAL OF THE SOCIETY OF TOXICOLOGY 1994; 23:237-50. [PMID: 7982532 DOI: 10.1006/faat.1994.1102] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Light gas oil (B-LGO), heavy gas oil No. 1 (B-HGOI), and heavy gas oil No. 2 (B-HGOII) fractions of bitumen upgrading products (BUPs) were applied on the dorsal skin of rats at 25 mg/kg bw/day (low dose), 100 mg/kg bw/day (intermediate dose), and 400 mg/kg bw/day (high dose) for 4 weeks. Control animals received normal saline while positive controls received a medium boiling coal liquefaction product (CLP) at 100 and 400 mg/kg bw/day. Reduced food comsumption and growth suppression were observed in males and females treated with B-HGOI, B-HGOII, and CLP, but only in males receiving B-LGO. Increased relative spleen, kidney, and liver weights were observed in animals treated with B-HGOI, B-HGOII, and CLP, but not in control or LGO groups. A dose-related increase in absolute and relative liver weight was most marked in animals receiving B-HGOII where a significant increase was observed starting at the low dose, followed by those receiving B-HGOI and CLP. Appearance of pale foci on the splenic capsule and increases in spleen/body weight ratio were limited to animals receiving B-HGOI and B-HGOII. Decreases in hematocrit and RBC and increase in percentage of reticulocytes were observed in animals of both sexes receiving B-HGOI and B-HGOII. Female rats appeared to be more severely affected because significant decreases in hemoglobin and RBC were observed in animals receiving the low dose of B-HGOII and the intermediate dose of B-HGO-I. Increased serum cholesterol was observed in B-HGOII-treated females at all dose levels, and in males starting at the intermediate dose. Histological changes were observed in the thymus gland, where moderate to marked cortical atrophy was noted in male and female rats receiving the high dose of B-HGOI and B-HGOII, and in the bone marrow, where the most significant abnormality was the presence of focal myelofibrosis in some male rats treated with B-HGOI and B-HGOII. Mild to moderate histological changes were found in the thyroid, liver, and spleen of rats of all treatment groups. Changes in the skin included moderate hyperkeratosis in females receiving high doses of B-LGO and in animals of both sexes receiving high doses of B-HGOI, and moderate to marked epidermal hyperplasia in rats receiving high doses of B-HGOI.(ABSTRACT TRUNCATED AT 400 WORDS)
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MacLellan K, Singh A, Chu I, Villeneuve DC. Subchronic toxicity of 3,3',4,4'-tetrachlorobiphenyl in the rat liver: an electron microscope study. Histol Histopathol 1994; 9:453-9. [PMID: 7981493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Ultrastructural effects of 3,3'4,4'-tetrachlorobiphenyl (PCB) congener #77 on the liver were evaluated following its feeding to Sprague-Dawley weanling rats. Treatment diets were prepared by dissolving the congener in 4% corn oil. Ten animals, either male or female, in each group were placed on the respective diets containing 10, 100, 1,000 and 10,000 ppb congener for 13 weeks. Ten animals of each sex served as the control that had only the oil added to the diets. In the congener-exposed animals the alterations consisted of a marked increase in the profiles of smooth endoplasmic reticulum, and in the heightened number of lipid droplets in many parenchymal cells. Several mitochondria showed abnormalities such as dumbbell shapes, and in others, the cristae were oriented parallel to the long axis of the organelle. Peroxisomes were numerous in the 10 ppb group and apparently had increased numerically in the liver of animals from the higher dose groups. Females were notably more affected by the congener when compared to their male counterparts. The results indicated that the compound is mildly toxic, and alteration in structure and function can be noted at the lowest dose used (10 ppb congener exposure). It is concluded that congener #77 may be moderately toxic and it may affect the overall health of the exposed animal.
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MacLellan K, Singh A, Chu I, Villeneuve DC. Toxicity of 2,2',4,4',5,5'-hexachlorobiphenyl in the rat liver: an electron microscope study. Histol Histopathol 1994; 9:461-8. [PMID: 7981494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Morphological effects on the liver of Sprague-Dawley rats administered orally 2,2',4,4',5,5'-hexachlorobiphenyl (PCB), congener #153, were analyzed. Treatment diets were prepared by dissolving the congener in 4% corn oil. Ten animals of either sex in each group were placed on the respective diets that contained 50, 500, 5,000, or 50,000 ppb congener. Ten animals of each sex served as the control that had only the oil added to the diets. Thirteen weeks after the onset of dosing, the animals were euthanized and liver samples were obtained from the animals and prepared for electron microscopy. Animals exposed to the congener showed (in a dose-related manner) a marked increase in smooth endoplasmic reticulum profiles, and in the number of lipid droplets in many parenchymal cells. Mitochondrial abnormalities such as dumbbell shapes, and in others, the cristae that were oriented parallel to the long axis of the organelle were present. The magnitude of morphologic alterations did not reveal gender differences. The results indicate mild hepatotoxicity of the congener in the rat.
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Poon R, Chu I, Bjarnason S, Potvin M, Vincent R, Miller RB, Valli VE. Inhalation toxicity study of methanol, toluene, and methanol/toluene mixtures in rats: effects of 28-day exposure. Toxicol Ind Health 1994; 10:231-45. [PMID: 7855870 DOI: 10.1177/074823379401000310] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The inhalation toxicity of methanol and toluene was investigated in rats. Young Sprague Dawley rats of both sexes were exposed to vapors of methanol (300 ppm, 3000 ppm), toluene (30 ppm, 300 ppm) or methanol/toluene (300/30 ppm, 300/300 ppm, 3000/30 ppm, and 3000/300 ppm) six hrs per day, five days/week for four weeks. Control animals inhaled air only. Increased serum alkaline phosphatase activity was observed in males exposed to high-dose toluene, and decreased creatinine was noted in the group exposed to high-dose methanol/toluene. The thyroid gland in females appeared to be a target organ for inhaled methanol, toluene, and methanol/toluene, although the changes were confined to a mild, and occasionally moderate, reduction in follicle size. Histopathological changes of the nasal passages, consisting of subepithelial nonsuppurative inflammation, occurred in higher incidences in rats exposed to methanol/toluene than in those exposed to the individual vapors. Inhalation of methanol, toluene, or methanol/toluene produced no changes in liver weights, hepatic mixed-function oxidases, or serum aspartate transaminase activities, and onlly minimal changes in liver histopathology. The only liver changes were decreased liver weight and increased cytoplasmic density of the periportal areas in females exposed to high-dose methanol/toluene. These data indicated that exposure to methanol, toluene, or a mixture of both produced mild biochemical effects and histological changes in the thyroid and nasal passage. No apparent interactive effects were observed.
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MacLellan K, Singh A, Chu I, Poon R, Villeneuve DC. Subchronic toxicity of pentachlorobiphenyl congeners n. 126 or 118 in the rat liver. An electron microscope study. JOURNAL OF SUBMICROSCOPIC CYTOLOGY AND PATHOLOGY 1994; 26:279-91. [PMID: 8019951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
3,3',4,4',5-Pentachlorobiphenyl (PCB) or congener n. 126 and 2,3',4,4',5-pentachlorobiphenyl or congener n. 118 were given independently to male and female Sprague-Dawley weanling rats. Experimental diets were prepared by dissolving the congeners in 4% corn oil. The congeners were administered as follows: congener n. 126--groups of three animals, either male or female, in each group were placed on the respective diets containing 0.1, 1.0, 10.0 ppb congener, 5.0 micrograms/kg bw loading dose + 10.0, or 100 ppb; congener n. 118--the females were dosed with 2, 20, 200, and 2,000 ppb congener, and the males received 10, 100, 1,000, 10,000 ppb. Thirteen weeks after the start of dosing with the two congeners, liver samples were obtained from all the animals and prepared for electron microscopy. In the congener n. 126-exposed animals, the alterations noted in a dose-related fashion consisted of a marked increase in the profiles of smooth endoplasmic reticulum (SER), and in the heightened number of lipid droplets in many parenchymal cells. Mitochondria showed abnormalities such as dumb-bell shapes, and the cristae parallel to the long axis of the organelle. Lipofuscin granules were numerous in the liver of animals that received 100 ppb of the congener; notably the females of the treatment group expressed this trait more abundantly than the males of the group. We conclude that the compound is mildly toxic. In the animals administered congener n. 118, the alterations were revealed in the liver of both male and female animals in a dose-related manner, also the most evident hepatocyte architectural modifications included an augmentation of SER profiles, mitochondrial aberrations, and an elevated number of lysosomal elements and lipid droplets. Abnormal shapes, and cristae in atypical orientation comprised mitochondrial aberrations. Alterations in the liver morphology of the females were qualitatively similar to those in the males; however, the dose levels used in the latter were five-folds of that which were given to the females. We conclude that the females are more sensitive than the males of the species to congener n. 118. We further conclude that congener n. 118 is less toxic than n. 126 since the lesions were induced by several-folds high dose levels used for the former.
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Chu I, Villeneuve DC, Yagminas A, LeCavalier P, Poon R, Feeley M, Kennedy SW, Seegal RF, Häkansson H, Ahlborg UG. Subchronic toxicity of 3,3',4,4',5-pentachlorobiphenyl in the rat. I. Clinical, biochemical, hematological, and histopathological changes. FUNDAMENTAL AND APPLIED TOXICOLOGY : OFFICIAL JOURNAL OF THE SOCIETY OF TOXICOLOGY 1994; 22:457-68. [PMID: 8050640 DOI: 10.1006/faat.1994.1051] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The systemic toxicity of 3,3',4,4',5-pentachlorobiphenyl (PCB 126) following subchronic dietary exposure was investigated in Sprague-Dawley rats. PCB 126 was administered to rats of both sexes at concentrations of 0.1, 1.0, 10, or 100 ppb in their diet for 13 weeks. Another group of rats received a loading dose of 5 micrograms PCB/kg body wt at the start of the feeding period followed by exposure to 10 ppb PCB diet for the same period of time as the other groups. Growth suppression and decreased food consumption were observed in the highest dose groups of both sexes. Increased organ/body weight ratios for the liver occurred in the 10 and 100 ppb groups of both sexes. Rats of both sexes exposed to the highest dose of the PCB also exhibited increased relative kidney, spleen, and brain weights. Hematological and most serum biochemical changes were confined to the 100 ppb groups. These included elevated alkaline phosphatase, bilirubin, cholesterol, and aspartate aminotransferase, and decreased serum glucose, hemoglobin, erythrocytes, hematocrit, and platelets. A dose-dependent increase in liver ethoxyresorufin-O-deethylase activity was observed in rats of both sexes starting at 0.1 ppb. A dose-dependent increase in liver uroporphyrin levels was observed in both sexes and significant changes occurred in the female rats at 1.0 ppb and higher dose groups. Decreased liver vitamin A was observed in the 10 ppb group and higher in both sexes. Kidney vitamin A was elevated in the 100 ppb group. No statistically significant changes were noted in concentrations of brain biogenic amines. PCB 126 residues were 10-fold higher in liver than in fat. Treatment-related histopathological changes were observed in the thymus, thyroid, bone marrow, and liver of rats exposed to the 10 ppb diet, but increased frequency of mild changes was observed in most of these tissues at the 1.0 ppb level. Based on the above data, the no adverse effect level was judged to be 0.1 ppb in the diet or 0.01 micrograms/kg body wt/day.
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Poon R, Villeneuve DC, Chu I, Kinach R. HPLC determination of D-glucaric acid in human urine. J Anal Toxicol 1993; 17:146-50. [PMID: 8336488 DOI: 10.1093/jat/17.3.146] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
An isocratic HPLC method has been developed for the direct measurement of D-glucaric acid in human urine. Pretreatment of urine with a boronic acid gel removed many interfering substances, including L-ascorbic acid and D-glucuronic acid. This method has a detection limit of 10 microM D-glucaric acid (approximately 7 mumoles/g creatinine). The run-to-run precisions were 9.1% and 7.7% at urinary D-glucaric acid concentrations of 41 and 219 mumoles/g creatinine, respectively. Urinary D-glucaric acid concentrations in normal adults were found to cover a range of 15 to 89 mumoles/g creatinine (mean = 47 mumoles/g creatinine). The sensitivity of this method in detecting abnormal elevations in D-glucaric acid was demonstrated through its ability to measure changes in urinary concentrations with time after ingestion of D-glucuronolactone.
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Moody RP, Nadeau B, MacDonald S, Chu I. In vitro skin absorption of 14C-cyanuric acid in a simulated swimming pool. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 1993; 50:12-18. [PMID: 8418925 DOI: 10.1007/bf00196534] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Chu I, Suzuki CA, Villeneuve DC, Valli VE. Systemic toxicity of the heavy fraction of a coal coprocessing product in male rats following subchronic dermal exposure. FUNDAMENTAL AND APPLIED TOXICOLOGY : OFFICIAL JOURNAL OF THE SOCIETY OF TOXICOLOGY 1992; 19:246-57. [PMID: 1516782 DOI: 10.1016/0272-0590(92)90158-e] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The systemic toxicity of a coal coprocessing product [heavy gas oil II (HGOII)] following subchronic, dermal exposure in male Sprague-Dawley rats was investigated. HGOII was applied to the dorsal skin daily at doses of 8.7, 20.8, 50.0, or 120.0 mg/kg body weight (bw) for 13 weeks. Another group of rats treated with a medium boiling coal liquefaction product (CLP) served as positive controls. Growth suppression and decreased food consumption were noted in the groups exposed to HGOII at 20.8 mg/kg and higher, and to CLP starting at the third week of treatment. Relative liver, kidney, and brain weights in the 20.8 mg/kg HGOII group and up were higher than those of the control. Increased spleen weight was observed in all HGOII-treated groups. CLP treatment also caused increased relative kidney and brain weights. Serum cholesterol was elevated in the HGOII-treated groups starting at 8.7 mg/kg while increased uric acid and lactate dehydrogenase were observed at 20.8 mg/kg and up. Decreased erythrocyte, hemoglobin, and platelet counts were observed at 20.8 mg/kg and higher. All HGOII-treated groups had elevated reticulocytes. These biochemical and hematological changes were not observed in the CLP-treated group. Mild to marked histological changes were observed in the thyroid, thymus, liver, spleen, and bone marrow of HGOII groups. In contrast, morphological changes were relatively mild in CLP-treated animals. Data from the present study demonstrated that the hematological endpoints were sensitive to the liquid fuels and that HGOII was more toxic than CLP.(ABSTRACT TRUNCATED AT 250 WORDS)
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Ng KM, Chu I, Bronaugh RL, Franklin CA, Somers DA. Percutaneous absorption and metabolism of pyrene, benzo[a]pyrene, and di(2-ethylhexyl) phthalate: comparison of in vitro and in vivo results in the hairless guinea pig. Toxicol Appl Pharmacol 1992; 115:216-23. [PMID: 1641855 DOI: 10.1016/0041-008x(92)90326-n] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The in vitro and in vivo absorption and metabolism of pyrene, benzo[a]pyrene, and di(2-ethylhexyl) phthalate (DEHP) were investigated in the hairless guinea pig. The in vitro method, which involved the use of flow-through diffusion cells and Hepes-buffered Hanks' balanced salt solution containing 4% bovine serum albumin as perfusate, was demonstrated to be a suitable system for predicting in vivo absorption of the above lipophilic compounds. The successful application of the in vitro technique for these compounds is significant because no satisfactory in vitro method has hitherto been developed to predict in vivo absorption of highly lipophilic chemicals. Quantification of parent compounds and metabolites that permeated into perfusates and those that remained in skin discs provided insight into the process by which the chemicals penetrated through the skin. Pyrene was absorbed primarily by a passive diffusion process, although a small fraction of the administered dose was biotransformed into metabolites in the skin and partitioned into the receptor fluid. Absorption of benzo[a]pyrene was mediated by biotransformation processes. A metabolite derived from the ultimate carcinogen of this compound, benzo[a]pyrene r-7, t-8,9,10-tetrahydrotetrol, was identified in the receptor fluid. Most of the administered DEHP remained in the skin and only a very small fraction of the dose partitioned into the receptor fluid in either viable or nonviable skin. Data from the present study led to the conclusion that the in vitro method can be utilized to predict in vivo absorption for compounds of high lipophilicity and that dermal metabolism facilitates partitioning of metabolites into the receptor fluid and hence may affect the biological activities of dermally applied compounds.
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Chu I, Villeneuve DC, Secours VE, Otson R, Valli VE. Short-term dermal toxicity and mutagenicity of coal coprocessing products in the rat. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH 1991; 33:317-26. [PMID: 1856879 DOI: 10.1080/15287399109531530] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The present study was conducted to determine the dermal toxicity of coal coprocessing products and to assess their potential health hazards. Groups of 10 male and 10 female Sprague-Dawley rats were administered dermally coal coprocessing products (light gas oil, LGO; heavy gas oil I, HGOI; heavy gas oil II, HGOII) at 1 g/kg body weight/d for 14 d. The control and positive control groups received normal saline and a coal liquefaction product (CLP) at the same dose level, respectively. Treatment with either the three fractions of coprocessing products or CLP caused decreased growth rate and food consumption in animals of both sexes. Liver enlargement occurred in groups treated with HGOI, HGOII, and CLP. Decreased serum glucose was observed in animals of both sexes treated with the three fractions and CLP. Treatment with HGOI and CLP caused an elevation of hepatic microsomal ethoxyresorufin deethylase activity in the rat of both sexes. The three fractions and CLP caused mild anemia. Mild treatment-related histological changes were observed in the liver, spleen, thyroid, bone marrow, and kidney. All three fractions of coprocessing products were tested for their mutagenicity in five strains of Salmonella typhimurium: TA98, TA100, TA1535, TA1537, and TA1538. HGOI, after metabolic activation, was found to be mutagenic in the strains of TA98, TA100, and TA1538. In contrast, HGOII was mutagenic in the five strains with or without metabolic activation. These data indicate that HGOI and HGOII are more toxic than LGO, and should be subjected to further studies to determine their long-term effects.
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Ng KM, Chu I, Bronaugh RL, Franklin CA, Somers DA. Percutaneous absorption/metabolism of phenanthrene in the hairless guinea pig: comparison of in vitro and in vivo results. FUNDAMENTAL AND APPLIED TOXICOLOGY : OFFICIAL JOURNAL OF THE SOCIETY OF TOXICOLOGY 1991; 16:517-24. [PMID: 1855623 DOI: 10.1016/0272-0590(91)90092-i] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The in vitro and in vivo percutaneous absorption/metabolism of phenanthrene was investigated in hairless guinea pigs. Flow-through diffusion cells and Hepes-buffered Hanks' balanced salt solution (HHBSS) as receptor fluid were used in the in vitro system. When phenanthrene was applied to excised guinea pig skin mounted on the cells at dose levels of 6.6 and 15.2 micrograms/cm2, 89.7 and 79.1% of the administered doses were respectively absorbed into the skin and receptor fluids during a 24-hr perfusion period. These results are consistent with the in vivo data which showed approximately 80% absorption over the same period of time. Phenanthrene was metabolized in vitro into phenanthrene 9,10-dihydrodiol, 3,4-dihydrodiol, 1,2-dihydrodiol, and traces of hydroxy phenanthrenes. Of the materials absorbed in vitro, 92% was the parent compound and 7% the dihydrodiol metabolites. When a nonviable in vitro system was used, 68% of the applied 15.2 micrograms/cm2 dose was absorbed. Data from the present study demonstrate that the in vitro system is a good model for predicting in vivo percutaneous absorption of phenanthrene, and that penetration of phenanthrene through the skin is controlled more by the passive rate of diffusion than by metabolism.
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Chu I, Villeneuve DC, Valli VE, Black WD, Robinson K, Beyrouty P. A teratological assessment of coal liquefaction products in the rat. J Appl Toxicol 1990; 10:411-6. [PMID: 2084180 DOI: 10.1002/jat.2550100606] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Teratogenicity of coal liquefaction products (CLP) was assessed in the pregnant rat. Three product streams of CLP (medium, hydrotreated medium and heavy fractions) were each administered dermally on Sprague-Dawley rats at doses of 125, 250 or 500 mg kg-1 day-1 from Day 6 through to Day 15 of gestation. Depressed maternal weight gain and reduced number of fetuses resulting from an increased resorption rate, decreased fetal weight and retarded ossification were observed in the group treated with the heavy fraction at a dose of 500 mg kg-1 day-1. The heavy fraction at 500 mg kg-1 day-1 also caused anaemia and increased liver and spleen weights in dams. The dams exposed to the highest dose of three CLP fractions had mild and adaptative hepatic changes consisting of increased cytoplasmic eosinophilia and nuclear anisokaryosis. No treatment-related histological changes were observed in fetuses. None of the fractions demonstrated any teratological effects.
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Chu I, Rinehart W, Hoffman G, Villeneuve DC, Otson R, Valli VE. Subacute inhalation toxicity of a medium-boiling coal liquefaction product (154-378 degrees C) in the rat [Part III]. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH 1989; 28:195-204. [PMID: 2795701 DOI: 10.1080/15287398909531340] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The short-term inhalation toxicity of a medium-boiling coal liquefaction product (CLP) was investigated in the rat. Groups of 5 male and 5 female Sprague-Dawley rats were exposed to CLP aerosols at 25 mg/m3 (low dose) or 100 mg/m3 (high dose) 6 h/d, 5 d/w, for 4 wk. The control group was exposed to filtered air while the positive control received diesel fuel aerosols at 100 mg/m3. Male rats exposed to high-dose CLP aerosols exhibited growth depression and increased hepatic aminopyrine demethylase activity compared to control animals. High-dose females had decreased hemoglobin content and hematocrit values. These biochemical and hematological effects were not observed in animals of either sex treated with the diesel fuel. No other biochemical and hematological changes were observed. Mild histological changes occurred in the liver and thyroid of rats treated with CLP and diesel fuel aerosols. Based on the data presented, inhalation of CLP aerosols resulted in toxicological effects that were similar to those caused by dermal exposure.
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Chu I, Villeneuve DC, Côté M, Secours V, Otson R, Valli VE. Dermal toxicity of a high-boiling (bp 250-450 degrees C) coal liquefaction product in the rat--II. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH 1988; 25:509-25. [PMID: 3199461 DOI: 10.1080/15287398809531228] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Coal liquefaction products have been considered as an alternate source of energy to replace conventional crude oil. The present study was designed to investigate the dermal toxicity of a heavy fraction of coal liquefaction product (CLP, bp 250-450 degrees C) in the rat. Groups of 10 male and 10 female Sprague-Dawley rats (180-200 g) were treated dermally with CLP at dose levels of 100, 200, 400, or 800 mg/kg body weight.d for 6 wk. The controls were treated with 0.4 ml/kg of normal saline, while the positive control group received 400 mg/kg diesel fuel. Growth suppression was observed in all CLP-treated groups of males; in the females this effect occurred in the two highest dose groups. Diesel fuel at 400 mg/kg also caused growth suppression of a similar magnitude to that of CLP in male rats. Male animals treated with high doses of CLP or diesel fuel had severe skin lesions. Increased liver weights were observed in the diesel fuel-treated as well as all CLP-treated groups of females. The kidney weights of females treated with 400 mg/kg and 800 mg/kg CLP were also higher than control values. Decreased red cell count, hemoglobin, and hematocrit volume occurred in some CLP and diesel fuel groups of both sexes. There was mild bone marrow hyperplasia in rats of both sexes treated with CLP or diesel fuel. Mild histological changes were observed in the thyroid, liver, bone marrow, and skin of rats of both sexes treated with CLP and diesel fuel. Based on the data presented, dermal application of CLP produced systemic toxicity at the dose levels studied, and CLP and diesel fuel possess toxic effects of similar nature and magnitude.
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Komsta E, Chu I, Villeneuve DC, Benoit FM, Murdoch D. Tissue distribution metabolism and excretion of 2,2',4,4',5-pentachlorodiphenyl ether in the rat. Arch Toxicol 1988; 62:258-62. [PMID: 3149180 DOI: 10.1007/bf00332484] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The tissue distribution, metabolism and excretion of 14C-2,2',4,4',5-pentachlorodiphenyl ether (PCDE) were studied in the rat. Radioactivity was distributed in all tissues examined, with the highest concentrations being found in the fat followed by the skin, liver, kidney and muscle. Most of the radioactivity found in the tissues was due to unchanged PCDE. Decay of PCDE in the blood was fitted to a four-compartment pharmacokinetic model, and the last compartment had a half-life of 5.8 days. A total of 55% and 1.3% of an orally administered dose was excreted in feces and urine, respectively, in 7 days. More than 64% of the fecal radioactivity was due to unchanged PCDE, while hydroxylated PCDE accounted for 23%.
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Chu I, Villeneuve DC, Côte M, Valli VE, Otson R. Dermal toxicity of a medium-boiling (154-378 degrees C) coal liquefaction product in the rat--Part I. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH 1988; 23:193-206. [PMID: 3343696 DOI: 10.1080/15287398809531106] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The subchronic dermal toxicity of a medium-boiling coal liquefaction product (CLP, 154-378 degrees C) was investigated in the rat. CLP was applied to the shaved backs of rats at dose levels of 50, 100, 200, or 400 mg/kg body weight.d, 7 d/wk for a period of 13 wk. Control groups received 0.4 ml/kg of normal saline. Signs of dermal irritation were observed at sites of application in males dosed at 200 and 400 mg/kg body weight and were characterized by thickened, focally necrotic and ulcerative skin. All animals survived the full length of the treatment period. Growth depression was observed in males at all dose levels, but no significant decrease in weight gain was observed in females. An increase in liver/body weight ratios was observed in all treatment groups of both sexes. The organ/body weight ratios for the spleen, heart, kidney, and brain were also increased in the upper dose groups of both sexes. Treatment with CLP caused a dose-dependent decrease in hemoglobin and packed cell volume in both sexes of all dose groups. The number of erythrocytes was decreased and that of neutrophils was increased in some CLP-treated groups of both sexes. There was a mild myeloid hyperplasia with increased myeloid/erythroid ratios in the 200- and 400-mg/kg groups of both sexes. Hepatic microsomal ethoxyresorufin deethylase activity was increased in all treatment groups of females, and in males dosed at 100 mg/kg and higher. In the renal tubules mild treatment-related histological changes occurred, which consisted of eosinophilic inclusions, increased cytoplasmic volume, and pyknosis. These changes were noted in the high-dose groups of both sexes. These data indicate that the medium-boiling CLP could produce systemic toxicity when applied dermally at 50 mg/kg body weight.d.
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Côté M, Chu I, Villeneuve DC, Secours VE, Valli VE. Trichlorobenzenes: results of a thirteen week feeding study in the rat. Drug Chem Toxicol 1988; 11:11-28. [PMID: 3378508 DOI: 10.3109/01480548809038653] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Trichlorobenzenes (TRCBs) are industrial chemicals and environmental pollutants found in Great Lakes fish. The present study was carried out to provide information on the toxic effects of these chemicals in mammals. Groups of male and female weanling rats were fed diets containing TRCB isomers at 1, 10, 100 or 1000 ppm for 13 weeks. The group of males fed 1000 ppm 1,2,3-TRCB diet had reduced weight gain. No other clinical signs of toxicity were observed. Increased relative liver and kidney weights occurred in the highest dose groups of males for all 3 TRCBs. Of the 3 isomers, only 1,2,4-TRCB at 1000 ppm caused increases in hepatic aminopyrine demethylase and aniline hydroxylase activities in male rats, and aminopyrine demethylase in females. Serum biochemical and hematological parameters measured were not affected. All three TRCBs produced histological changes of a moderate degree in the liver and thyroid of male rats at 1,000 ppm. Only 1,3,5-TRCB elicited moderate renal changes in male rats fed 1,000 ppm. Microscopic changes in the females were generally milder than those of the corresponding males. Based on these data it was concluded that the nonobservable adverse effect levels for the three TRCBs were 100 ppm in the diet, or 7.6 approximately 7.8 mg/kg b.w./day depending on the dietary consumption.
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Schwartz H, Chu I, Villeneuve DC, Benoit FM. Metabolism of 1,2,3,4-, 1,2,3,5-, and 1,2,4,5-tetrachlorobenzene in the squirrel monkey. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH 1987; 22:341-50. [PMID: 3682021 DOI: 10.1080/15287398709531076] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The metabolism of three tetrachlorobenzene isomers (TeCB) was investigated in the squirrel monkey. The animals were administered orally 6 single doses of 14C-labeled 1,2,3,4-, 1,2,4,5-, or 1,2,3,5-tetrachlorobenzene over a 3-wk period at levels ranging from 50 to 100 mg/kg body weight (b.w.) and kept in individual metabolism cages to collect urine and feces for radioassay. Approximately 38% (1,2,3,4-TeCB), 36% (1,2,3,5-TeCB), and 18% (1,2,4,5-TeCB) of the doses were excreted respectively in the feces 48 h postadministration. In monkeys dosed with 1,2,3,4-TeCB, unchanged compound accounted for 50% of the fecal radioactivity; its fecal metabolites were identified as 1,2,4,5-tetrachlorophenol (TeCP, 22%), N-acetyl-S-(2,3,4,5-tetrachlorophenyl) cysteine (18%), 2,3,4,5-tetrachlorophenyl sulfinic acid (3%), 2,3,4-trichlorophenyl methyl sulfide (0.6%), and 2,3,4,5-tetrachlorophenyl methyl sulfide (0.2%). As was the case with 1,2,3,4-TeCB, unchanged compound accounted for more than 50% of the fecal radioactivity found in the monkeys dosed with 1,2,3,5-TeCB. The fecal metabolites of 1,2,3,5-TeCB consisted of 2,3,4,5-TeCP (2%), 2,3,4,6-TeCP (14%), 2,3,5,6-TeCP (9%), and 2,3,5,6-tetrachlorophenyl sulfinic acid (15%). No metabolites were detected in the feces of monkeys dosed with 1,2,4,5-TeCB. While the fecal route represented the major route of excretion for 1,2,3,4-TeCB, the other two isomers were eliminated exclusively in the feces. The above data in the squirrel monkey are different from those obtained with the rat and the rabbit, and demonstrate the different metabolic pathways for the isomers.
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