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1.
Nanoscale Res Lett ; 17(1): 47, 2022 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-35435525

RESUMO

Ni nanoparticle catalysts embedded in ZrO2 porous spheres and ZrO2 porous composite spheres, SiO2-ZrO2, MgO-ZrO2, and Y2O3-ZrO2, with 83-115 nm diameter and 167-269 m2/g specific surface area were prepared by a one-pot and one-step solvothermal reaction from precursor solutions consisting of Ni(NO3)2‧6H2O, Zr(OnBu)4, and acetylacetone in moist ethanol combined with either Si(OEt)4, magnesium acetylacetate, or Y(OiPr)3. The obtained Ni catalysts have high specific surface areas of 130-196 m2/g, even after high-temperature reduction by H2 at 450 °C for 2 h. They were utilized as catalysts for low-temperature dry reforming of methane (DRM) at 550 °C to suppress carbon deposition on Ni nanoparticles. The Ni catalysts embedded in SiO2-ZrO2 and Y2O3-ZrO2 demonstrated high catalytic activity and long stability in the reaction. Moreover, carbon deposition on Ni nanoparticles in the DRM reaction was effectively suppressed in when using the SiO2-ZrO2 and Y2O3-ZrO2 composites.

2.
J Toxicol Pathol ; 27(1): 87-90, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24791072

RESUMO

The development of ectopic gastric, intestinal, or pancreatic tissue in the gastrointestinal tract is extremely rare in rats, although it is fairly common in humans. In this report, we describe an unusual case in which a mixture of different types of ectopic tissue was found in the forestomach of a rat. A solitary white nodular/polypoid structure, which measured 5 mm in size, was detected on the luminal surface of the greater curvature of the forestomach in an 8-week-old female Crl:CD(SD) rat. A histological examination revealed that the lesion contained ectopic glandular gastric tissue, including gastric surface mucous cells, parietal cells, and pyloric gland cells, which was confirmed by immunohistochemistry. Moreover, the lesion also contained villin-positive columnar intestinal absorptive cells and chymotrypsin-positive pancreatic exocrine tissue. To the best of our knowledge, this is the first study to detect a mixture of ectopic glandular gastric, intestinal, and exocrine pancreatic tissue in a rat.

3.
J Vet Med Sci ; 75(12): 1667-9, 2013 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-23955395

RESUMO

A 10-year-old female sea otter exhibited convulsions, arrhythmia, hyperthermia, forced breathing and anorexia and died after a week. Histopathological examination revealed neoplastic proliferation of small round cells with scant cytoplasm and round or oval nuclei distributed mainly in the thalamus. The proliferation of neoplastic cells was observed in the cerebral parenchyma and perivascular areas. The neoplastic cells were immunopositive for CD3, but not CD20. No neoplastic proliferation of T-cells was found in other organs. Taken together, we diagnosed this case as a primary cerebral T-cell lymphoma. To our knowledge, this is the first case of primary cerebral T-cell lymphoma in a sea otter.


Assuntos
Animais de Zoológico , Neoplasias Encefálicas/veterinária , Linfoma de Células T/veterinária , Lontras , Animais , Neoplasias Encefálicas/patologia , Complexo CD3/imunologia , Evolução Fatal , Feminino , Técnicas Histológicas/veterinária , Linfoma de Células T/patologia
4.
J Toxicol Sci ; 37(4): 723-37, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22863853

RESUMO

The present study aimed to establish candidate biomarker genes for the early detection of nephrotoxicity in mice, with a particular focus on nephrotoxicity caused by polyene macrolides. Comprehensive gene expression changes were evaluated using microarrays in a mouse model in which acute nephrotoxicity was induced by amphotericin B deoxycholate, trade name Fungizone. The upregulated genes identified through microarray analysis of kidney tissue of Fungizone-treated mice included several genes that have been reported as nephrotoxicity biomarkers in rats, and 14 genes were selected as candidate nephrotoxicity biomarkers. The usefulness of these genes as nephrotoxicity biomarkers in mice was evaluated further through expression profiling under several experimental conditions using real time RT-PCR. Expression of genes encoding kidney injury molecule 1, lipocalin 2, tissue inhibitor of metalloproteinase 1, and secreted phosphoprotein 1 was highly upregulated by Fungizone, nystatin, natamycin, amphotericin B methyl ester, and liposomal amphotericin B, and their area under the ROC curve values were more than 0.95. These genes were more sensitive at detecting nephrotoxicity than traditional clinical chemistry and histopathology parameters. This study provides novel evidence that these nephrotoxicity biomarker genes identified are translatable to mice, and that they are useful for early and sensitive detection of nephrotoxicity.


Assuntos
Anfotericina B/toxicidade , Ácido Desoxicólico/toxicidade , Rim/efeitos dos fármacos , Rim/patologia , Proteínas de Fase Aguda/genética , Proteínas de Fase Aguda/metabolismo , Anfotericina B/análogos & derivados , Animais , Antibacterianos/toxicidade , Relação Dose-Resposta a Droga , Combinação de Medicamentos , Expressão Gênica , Perfilação da Expressão Gênica , Marcadores Genéticos , Receptor Celular 1 do Vírus da Hepatite A , Hibridização In Situ , Rim/metabolismo , Lipocalina-2 , Lipocalinas/genética , Lipocalinas/metabolismo , Masculino , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos ICR , Análise em Microsséries , Modelos Animais , Natamicina/toxicidade , Nistatina/toxicidade , Proteínas Oncogênicas/genética , Proteínas Oncogênicas/metabolismo , Osteopontina/genética , Osteopontina/metabolismo , Polienos/efeitos adversos , Ratos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Inibidor Tecidual de Metaloproteinase-1/genética , Inibidor Tecidual de Metaloproteinase-1/metabolismo , Regulação para Cima
5.
Toxicology ; 290(2-3): 241-8, 2011 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-22005293

RESUMO

Recent research has revealed several useful urinary biomarkers of renal dysfunction such as acute kidney injury (AKI). For adequate evaluation of altered urinary biomarkers, it is necessary to consider the influence of varied urine flow rate (UFR). Calculation of the excretion rate of a urinary biomarker (UFR-correction) is the gold standard for the correction of UFR variation. An alternative method that is widely used is to calculate the ratio of the biomarker level to urinary creatinine (Ucr-correction). To date, the equivalence between these two methods has been examined only in a steady state situation such as diabetic nephropathy, and the urinary biomarkers examined have been limited to proteinuria and albuminuria. Therefore, we comprehensively addressed the relationship between Ucr-correction and UFR-correction of ten urinary biomarkers N-acetyl-ß-d-glucosaminidase (NAG), lactate dehydrogenase (LDH), total protein, albumin, kidney injury molecule-1, neutrophil gelatinase-associated lipocalin, clusterin, ß(2)-microglobulin, cystatin-c and glutathione S-transferase-α in non-steady state situations such as AKI. All ten urinary biomarkers showed larger amplitude increases in AKI by Ucr-correction than by UFR-correction in linear regression analysis. Moreover, receiver operating characteristic curves analysis suggested that, at least for the biomarkers NAG and LDH, Ucr-correction had higher diagnostic power than UFR-correction. We observed a decrease in the Ucr excretion in AKI that was accompanied by a reduction in creatinine clearance and reduced mRNA expression of the renal organic cation transporter-2, which is known to function as a transporter for creatinine. These results may provide a mechanistic explanation for the phenomena obtained in Ucr-correction. In conclusion, while Ucr-correction could overestimate the degree of AKI, it could also provide higher diagnostic power for AKI than UFR-correction. We should take into consideration of these backgrounds when using the Ucr-correction.


Assuntos
Injúria Renal Aguda/diagnóstico , Biomarcadores/urina , Creatinina/urina , Proteínas de Transporte de Cátions Orgânicos/genética , Injúria Renal Aguda/fisiopatologia , Animais , Regulação da Expressão Gênica , Modelos Lineares , Masculino , Transportador 2 de Cátion Orgânico , RNA Mensageiro/metabolismo , Curva ROC , Ratos , Ratos Sprague-Dawley
6.
Rinsho Ketsueki ; 52(1): 32-6, 2011 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-21378480

RESUMO

We encountered a patient with cold agglutinin disease (CAD) that worsened after Salmonella gastroenteritis. A 52-year-old male complained pain in the left fingers with cyanosis and was admitted in a local hospital. After treatment for ischemia, he demonstrated diarrhea with fever. Because of progressive anemia, he was referred to our hospital. Salmonella gastroenteritis was diagnosed based on the results of microbiological examination. Severe hemolysis was noted at admission, and Coombs test was positive (IgG-, C3d+). Cold agglutinin titer was elevated (x256). There were no findings of malignancy or infection demonstrating CA. A diagnosis of CAD with Salmonella gastroenteritis was made. Because spherocytosis was noted during admission, we measured the mean channel fluorescence (MCF) of eosin-5-maleimide (EMA) in erythrocytes from patients. MCF of EMA of the patient's erythrocytes was similar to that of normal subjects. Therefore, we concluded that coexisting hereditary spherocytosis was unlikely. We also examined the in vitro hemolytic effect of Salmonella infection on his blood and on blood from normal subjects. Treatment with Salmonella enteritidis isolated from this patient was found to induce hemolysis in the patient's blood, but not in blood from a normal subject. Moreover, treatment with Salmonella increased the titer of cold agglutinin in vitro. These data suggested that Salmonella infection might worsen hemolysis in CAD.


Assuntos
Anemia Hemolítica Autoimune/etiologia , Gastroenterite/complicações , Gastroenterite/microbiologia , Infecções por Salmonella , Anemia Hemolítica/etiologia , Amarelo de Eosina-(YS)/análogos & derivados , Humanos , Masculino , Pessoa de Meia-Idade
7.
J Toxicol Pathol ; 24(4): 257-61, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22319240

RESUMO

Endogenous prostaglandin (PG) E(2) plays important roles in renal homeostasis. Immunoexpressions of PGE(2) biosynthesis-related enzymes, cyclooxygenase (COX)-2 and microsomal PGE(2) synthetase (mPGES)-1 and EP4 (a PGE(2) receptor), were investigated in renal development. Kidney tissues were obtained from fetuses on gestation days 18 and 21 and neonates on days 1 to 18. In fetuses and early neonates, the expressions of COX-2, mPGES-1 and EP4 were observed in developing renal tubules, indicating that COX-2 and its product, PGE(2), play important roles in blastemal cell-derived renal tubular development via EP4. Cyclin D1 expression was seen in both the nucleus and cytoplasm of the developing tubules. These findings differed from the decreased COX-2 expression and exclusive nuclear expression of cyclin D1 seen in abnormal epithelial regeneration of injured renal tubules in cisplatin-treated rats in our previous articles. Collectively, PGE(2), induced by COX-2, regulates renal tubular epithelial formation via EP4.

8.
J Vet Med Sci ; 73(4): 527-30, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21139353

RESUMO

A 3-year-old, spayed female miniature dachshund was presented for vomiting and anorexia. Thoracic radiographs and CT scan revealed abnormal pulmonary opacities at bilateral caudal lobe. Cytological analysis of the pulmonary mass revealed the presence of large lymphohistiocytic cells and small lymphocytes with occasional neutrophils and plasma cells. An open lung biopsy was performed and a diagnosis of pulmonary lymphomatoid granulomatosis (LYG) was made. The dog was administered CHOP based therapy (modified UW-25), and it survived for 1,022 days after admission. Immunohistochemistry revealed pulmonary lesions consisted of many CD79a positive B cells aggregation and proliferation with prominent angiocentric pattern. This was the first case of canine pulmonary LYG managed by CHOP chemotherapy.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Doenças do Cão/tratamento farmacológico , Neoplasias Pulmonares/veterinária , Granulomatose Linfomatoide/veterinária , Animais , Ciclofosfamida/uso terapêutico , Cães , Doxorrubicina/uso terapêutico , Feminino , Neoplasias Pulmonares/tratamento farmacológico , Granulomatose Linfomatoide/tratamento farmacológico , Prednisona/uso terapêutico , Vincristina/uso terapêutico
9.
Histol Histopathol ; 25(8): 985-94, 2010 08.
Artigo em Inglês | MEDLINE | ID: mdl-20552549

RESUMO

Macrophages play important roles in host defense and homeostasis. In contrast to adulthood, far less is known about macrophage populations in fetuses and neonates. Macrophages were evaluated in the developing rat skin at different anatomical sites (head, anterior dorsal, posterior dorsal, and abdomen) of F344 rats obtained on gestational days 18 and 20, on neonatal days 1-21, and at adult weeks 5-15. The numbers of macrophages in the epidermis, dermis or perifollicular areas that were positive for ED1 (exudative macrophages with activated phagocytosis), ED2 (resident macrophages), and OX6 (antigen-presenting cells) were evaluated. There were no differences in macrophage numbers among the anatomical sites. In the epidermis, only OX6 cells were seen, with gradually increased numbers in neonates and adults. In the dermis, many ED1 cells were already seen in fetuses, and the number peaked on neonatal day 4, and remained at that level until adulthood. By contrast, ED2 and OX6 cells began to be seen after birth and their numbers continued to increase until adulthood; ED2 cells were distributed diffusely in the dermis, whereas ED1 and OX6 cells were present exclusively in the upper dermis. In perifollicular areas, ED1, ED2 and OX6 cells began to be seen after birth, and their numbers gradually increased until adulthood. Some macrophages in dermal and perifollicular areas gave double-positive reactions to ED1+ED2+, ED1+OX6+ or OX6+ED2+. Increased mRNA levels of colony stimulating factor-1 and monocyte chemoattractant protein-1 appeared to correspond to the emergence of rat macrophages. Skin macrophages were shown to be heterogeneous in distribution and function; the information from this study should be very useful for future investigations of experimentally induced rat skin lesions.


Assuntos
Macrófagos/imunologia , Macrófagos/patologia , Ratos Endogâmicos F344/embriologia , Ratos Endogâmicos F344/imunologia , Animais , Animais Recém-Nascidos , Células Apresentadoras de Antígenos/imunologia , Quimiocina CCL2/genética , Quimiocina CCL2/imunologia , Feto/imunologia , Fagocitose/imunologia , RNA Mensageiro/imunologia , Ratos
10.
Histol Histopathol ; 25(8): 995-1007, 2010 08.
Artigo em Inglês | MEDLINE | ID: mdl-20552550

RESUMO

In the kidney, prostaglandin (PG) E2 is the main PG, playing important roles in maintaining homeostasis or development of pathological settings. Roles of PGE2 in renal lesions remain to be clarified. The expression patterns of PGE2 synthesis enzymes such as cyclooxygenase (COX)-1, COX-2 and microsomal PGE synthase (mPGES)-1, and PGE2 receptors (EP2 and EP4) were examined in cisplatin-induced rat renal failure. The immunoexpressions for COX-1, mPGES-1 and EP4 receptor were increased exclusively in the affected renal tubules, but those of COX-2 and EP2 receptor were not detected; increased expression of COX-1 was confirmed at mRNA level. Using rat renal epithelial cell line (NRK-52E), the effects of PGE2 on cell proliferation were investigated. The addition of PGE2 or 11-deoxy-PGE1 (EP4 receptor agonist) to NRK-52E increased the cell number, indicating the effects of PGE2 via EP4 receptor. Furthermore, 11-deoxy-PGE1-treated NRK-52E cells underwent the G0/G1 arrest and decreased apoptosis. NRK-52E treated with transforming growth factor (TGF)-beta1, an inducer of epithelial-mesenchymal transition (EMT), in the presence of 11-deoxy-PGE1 decreased the mRNA expression of alpha-smooth muscle actin (a marker of myofibroblasts). Collectively, the present study shows that COX-1 plays more important roles than dose COX-2 in cisplatin-induced rat renal failure; the product, PGE2, may regulate renal epithelial regeneration via EP4 receptor through inhibition of apoptosis and EMT.


Assuntos
Dinoprostona/metabolismo , Alprostadil/análogos & derivados , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular , Cisplatino/metabolismo , Cisplatino/farmacologia , Ciclo-Oxigenase 1/metabolismo , Ciclo-Oxigenase 1/farmacologia , Ciclo-Oxigenase 2/metabolismo , Ciclo-Oxigenase 2/farmacologia , Dinoprostona/farmacologia , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Oxirredutases Intramoleculares , Rim/metabolismo , Túbulos Renais/metabolismo , Masculino , Prostaglandina-E Sintases , Ratos , Ratos Endogâmicos F344 , Receptores de Prostaglandina E/metabolismo , Receptores de Prostaglandina E/fisiologia , Receptores de Prostaglandina E Subtipo EP2 , Receptores de Prostaglandina E Subtipo EP4 , Regeneração/efeitos dos fármacos , Fator de Crescimento Transformador beta1/metabolismo , Fator de Crescimento Transformador beta1/farmacologia
11.
J Toxicol Pathol ; 23(2): 91-4, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22272017

RESUMO

A young male Crl:CD (SD) rat with erythroid leukemia that presented with emaciation, abdominal distension and a pale visible mucosal membrane was euthanized at 7 weeks of age. At necropsy, enlargement of liver, spleen and pancreatic lymph node was noted. Analysis of blood smear samples revealed many mono- or binucleated erythroblasts that had PAS-positive vacuoles in the cytoplasm. Histopathologically, neoplastic proliferation of atypical cells was observed in the hepatic sinusoids, splenic red pulp, bone marrow, pancreatic lymph node, kidney and lung. Neoplastic cells showed a round to spindle shape, and some neoplastic cells had deeply stained small nuclei and small cytoplasms and resembled erythroblasts. Immunohistochemically, many neoplastic cells were positive for hemoglobin. To our knowledge, this is the first report of erythroid leukemia in a rat of this age. The observed features were similar to those of pure erythroid leukemia in humans.

12.
J Toxicol Pathol ; 23(4): 271-5, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22272038

RESUMO

Cisplatin, an anticancer drug, is well known to have nephrotoxicity as an adverse effect. We investigated the expressions of cell cycle markers and prostaglandin E(2) (PGE(2)) receptors (EP) in the affected renal tubules in rats injected with a single dose (6 mg/kg body weight) of cisplatin. On days 1-3 after dosing, the affected renal epithelial cells were almost desquamated, showing necrosis. On day 5 onwards, the renal tubules were rimmed by flattened or cuboidal epithelial cells with basophilic cytoplasm; BrdU-immunopositive cells began to significantly increase, indicating regeneration. Simultaneously, TUNEL-positive apoptotic cells were also seen. On days 1-5, cyclin D1-immunopositive cells were decreased with an increased expression in p21 mRNA, indicating G(1) arrest in the cell cycle. The affected renal epithelial cells began to react to EP4 receptor, but not to EP2 receptor. Some EP4 receptor-reacting epithelial cells gave a positive reaction to BrdU or cyclin D1. Collectively, the affected renal tubules underwent various alterations such as necrosis, apoptosis, regeneration and G(1) arrest; the aspects might be influenced by endogenous PGE(2) through EP4 receptor.

13.
J Oleo Sci ; 57(9): 513-9, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18685234

RESUMO

Crystal structures of 2-aminotropone (1), N,N'-di(tropon-2-yl)piperazine (2), and 5-(4-ethoxyphenylazo)tropolone (3) have been elucidated by X-crystallographic analysis. 2-Aminotropone (1) contains three crystallographically independent molecules in the crystal lattice. The NH2 groups of 2-aminotropone unit of 1 participate in the N-H...O intermolecular hydrogen bonds. Two tropone units of N,N'-di(tropon-2-yl)piperazine (2) have an anti orientation to the piperazine ring. The crystal packing of 2 is consolidated by pi...pi, C-H...pi, and C-H...O interactions. 5-(4-Ethoxyphenylazo)tropolone (3) forms O-H...O hydrogen bond dimmers about inversion centres, involving the OH group and an intermolecular carbonyl O acceptor.


Assuntos
Compostos Azo/síntese química , Materiais Biocompatíveis/química , Piperazinas/síntese química , Tropolona/análogos & derivados , Tropolona/síntese química , Aminas/química , Cristalografia por Raios X , Dimerização , Ligação de Hidrogênio , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Conformação Molecular
14.
Exp Anim ; 56(5): 379-84, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18075199

RESUMO

The ground squirrel is used as an experimental animal because of its unique biological nature. A 3-year-old female Richardson's ground squirrel developed a mass, 1.5 cm in diameter, in the buccal mucosa. The mass consisted of neoplastic epithelial cells showing acinar, ductular, intraductal papillary, solid, and lobular growth patterns; the cells were immunoreactive to cytokeratin, cyclooxygenase-2 (a marker of malignancy) and TGF-beta1. After resection, the tumor recurred with increased area having a solid or lobular pattern with little differentiation. This tumor was diagnosed as an adenocarcinoma arising from the buccal gland, the first case reported in the ground squirrel. A prominent desmoplastic reaction was present. The interstitial cells reacted to alpha-smooth muscle actin and vimentin, indicating a myofibroblastic nature, presumably induced by epithelial TGF-beta1.


Assuntos
Adenocarcinoma/veterinária , Ciclo-Oxigenase 2/imunologia , Doenças dos Roedores/imunologia , Neoplasias das Glândulas Salivares/veterinária , Sciuridae , Fator de Crescimento Transformador beta1/imunologia , Adenocarcinoma/imunologia , Adenocarcinoma/patologia , Animais , Feminino , Imuno-Histoquímica , Mucosa Bucal , Doenças dos Roedores/patologia , Neoplasias das Glândulas Salivares/imunologia , Neoplasias das Glândulas Salivares/patologia
15.
Biol Blood Marrow Transplant ; 12(4): 408-13, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16545724

RESUMO

Although the mobilization of peripheral blood stem cells from normal donors using granulocyte colony-stimulating factor is widely used, the ideal method for the administration of filgrastim has not been determined. Therefore, we compared the efficacy of peripheral blood stem cell mobilization on day 4 of filgrastim between once-daily (group O) and twice-daily (group T) administration of filgrastim at 400 microg/m(2)/d. In all, 38 and 34 donors were randomly assigned to groups O and T, respectively. The number of CD34(+) cells collected on day 4 was not significantly different (1.74 x 10(6) cells/kg in group O and 2.08 x 10(6) cells/kg in group T, P = .37). The incidence and severity of adverse events were similar in the two groups. The baseline white blood cell count was the strongest predictor of poor mobilization. Donor age, sex, and serum concentrations of several cytokines did not significantly affect the CD34(+) cell yield. In conclusion, once-daily administration of filgrastim at 400 microg/m(2)/d appeared to be appropriate for the mobilization of CD34(+) cells in normal donors when apheresis is planned on day 4 of filgrastim. Selection of a donor with a steady-state white blood cell count of 5.0 x 10(9)/L or more may lead to a lower incidence of poor mobilization.


Assuntos
Antígenos CD34 , Doadores de Sangue , Fator Estimulador de Colônias de Granulócitos/administração & dosagem , Mobilização de Células-Tronco Hematopoéticas , Células-Tronco Hematopoéticas , Adolescente , Adulto , Idoso , Feminino , Filgrastim , Mobilização de Células-Tronco Hematopoéticas/métodos , Células-Tronco Hematopoéticas/citologia , Humanos , Contagem de Leucócitos/métodos , Masculino , Pessoa de Meia-Idade , Proteínas Recombinantes
16.
Toxicol Pathol ; 32(5): 519-26, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15603537

RESUMO

The placenta plays an important role in the regulation of maternal to fetal transfer of toxic substances, including nonessential metals. Metallothioneins (MTs), which are known to have protective effects against heavy metal toxicity, exist in the placenta, but the exact localization of placental MTs (both MT-I and MT-III) and their physiological role in the placenta exposed to mercury are unclear. The present study was performed to examine the localization of MTs and mercury granules in the placenta of mice exposed to mercury vapor. On gestational day 16, MT-I & II-null and wild-type mice were exposed to mercury vapor at 4.9 to 5.9 mg/m3 for 2 hours. At 24 and 48 hours after exposure, the placentas were examined for mercury distribution (autometallography), MT immunoreactivity, and MT mRNA expression (in situ hybridization). No histological changes were observed in the placentas of either MT-null or wild-type mice. Mercury deposition was demonstrated along the boundary between the junctional zone and the labyrinth zone, as well as in the yolk sac, maternal decidual cells, and labyrinth trophoblasts of both MT-null and wild-type mice. MT-I & -II immunoreactivity, which was confined to wild-type mice, was demonstrated in the yolk sac and decidual cells; mercury was also shown in both structures, suggesting that mercury granules were bound to MTs. MT-III mRNA expression was observed in the yolk sac, decidual cells, and spongiotrophoblasts in both MT-null and wild-type mice. There was, however, no evidence of MT at the boundary between the junctional and labyrinth zones, where substantial mercury deposits were demonstrated. These results suggest that placental MTs and the other unknown molecules may be related to the barrier to the placental transfer of mercury.


Assuntos
Exposição Materna , Troca Materno-Fetal/fisiologia , Mercúrio/toxicidade , Metalotioneína/deficiência , Placenta/efeitos dos fármacos , Placenta/ultraestrutura , Administração por Inalação , Animais , Relação Dose-Resposta a Droga , Feminino , Técnica Indireta de Fluorescência para Anticorpo , Predisposição Genética para Doença , Técnicas Imunoenzimáticas , Hibridização In Situ , Exposição por Inalação , Intoxicação por Mercúrio/genética , Intoxicação por Mercúrio/patologia , Metalotioneína/genética , Metalotioneína/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Placenta/metabolismo , Gravidez , RNA Mensageiro/metabolismo
17.
Toxicology ; 175(1-3): 215-22, 2002 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-12049849

RESUMO

This study examined the role of placenta metallothionein (MT) in maternal-to-fetal mercury transfer in MT-null and wild-type mice after exposure to elemental mercury (Hg(0)) vapor. Both strains were exposed to Hg(0) vapor at 5.5-6.7 mg/m(3) for 3 h during late gestation. Twenty-four hours after exposure to Hg(0) vapor, accumulation of mercury in the major organs, except the brain, of MT-null maternal mice was significantly lower than that in organs of wild-type mice. In contrast to mercury levels in maternal organs, fetal mercury levels were significantly higher in MT-null mice than in wild-type mice. In placenta, mercury concentrations were not significantly different between the two strains. Although MT levels in major organs, except the brain, of wild type mice were markedly elevated after the exposure to Hg(0) vapor, the placental MT levels were not elevated. However, endogenous MT level in the placenta is significantly higher than that in other organs, except the liver. Gel filtration profile of the placental cytosol in the wild-type mice revealed that a large amount of placental mercury was associated with MT. In MT-null mice, mercury in placental cytosol appeared mainly in the high-molecular-weight protein fractions. Mercury in the placenta was localized mainly in the yolk sac and decidual cells in the deep layer of the decidua in both mouse strains. The similar localization of MT was found in the placenta of wild type mice. These results suggest that MT in the placenta has a defensive role in preventing maternal-to-fetal mercury transfer.


Assuntos
Exposição Materna/efeitos adversos , Troca Materno-Fetal/fisiologia , Mercúrio/farmacocinética , Metalotioneína/deficiência , Placenta/metabolismo , Administração por Inalação , Animais , Cromatografia em Gel , Desenvolvimento Embrionário e Fetal/efeitos dos fármacos , Feminino , Imuno-Histoquímica , Masculino , Mercúrio/administração & dosagem , Mercúrio/toxicidade , Metalotioneína/metabolismo , Metalotioneína/fisiologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Gravidez , Saco Vitelino/metabolismo
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