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Biomedical subjects

A Naganuma

Publications and source records attributed to A Naganuma.

101 records · Page 6Linked to original sources
PubMed1980

Changes in distribution of mercury and selenium in soluble fractions of rabbit tissues after simultaneous administration.

The existing states of mercury and selenium in the blood and in soluble fractions of perfused rabbit liver and kidney were studied by gel filtration on Sephadex G-200 1 hr or 24 hr after intravenous injection of mercuric chloride and/or sodium selenite. Both mercury and selenium in the plasma and stroma-free hemolysate were found to exist in the high-molecular weight fraction following simultaneous injection of mercuric chloride and sodium selenite. Patterns in gel filtration of the plasma and the stroma-free hemolysate did not show any significant change between 1 hr and 24 hr after the administration. A similar tendency as described above was obtained with the liver-soluble fraction at 24 hr after injection of mercuric chloride and sodium selenite. A possible role of the high-molecular weight complex, which is quickly formed by the interaction of mercury and selenium in blood stream, in decreasing the acute renal toxicity of inorganic mercury is discussed.

Animals↗
PubMed1980

Bis(methylmercuric) selenide as a reaction product from methylmercury and selenite in rabbit blood.

The compound formed by the reaction of methylmercury and selenite in rabbit blood was characterized. When methylmercuric chloride (10 nmol) and sodium selenite (10 nmol) were added to rabbit blood (1 ml), about 6.5 nmol of mercury and 3.2 nmol of selenium were extracted with benzene. Mercury and selenium thus transferred into benzene at the molar ratio of 2 : 1 were confirmed to form a single compound which was identified as bis(methylmercuric) selenide :(CH3Hg)2Se. The formation of (CH3Hg)2Se from methylmercury and selenite in blood, presumably by the participitation of glutathione (GSH), might play a role in the protective effect of selenium against methylmercury toxicity.

Animals↗
PubMed1978

In vitro studies on interaction of mercuric mercury and selenite in rabbit blood.

The behaviors of inorganic mercury and selenite in rabbit blood, added in vitro individually or in combination, were investigated. Inorganic mercury incorporated into erythrocyte in the absence of selenite was mainly present in the fractions which were eluted from Sephadex G-200 column just after hemoglobin. On the other hand selenium incorporated into erythrocyte in the absence of mercury was eluted in hemoglobin fractions and also in those which are almost completely retained by the column. In the combination experiment, however, the incorporation of mercury and selenium was remarkably enhanced and the increased amounts of both the compounds were eluted together with each other around the void volume region of the Sephadex G-200 column. The existing state of mercury and selenium in the high-molecular weight fractions and the effects of some metabolic inhibitors on the behavior of these compounds in blood were also studied.

Animals↗
PubMedDate not supplied

Protective effect of metallothionein inducing metals on lethal toxicity of cis-diamminedichloroplatinum in mice.

A protective effect of preadministration of the metals Cu, Bi, Zn, Hg, Cd, Ni or Co, against lethal toxicity of cis-diamminedichloroplatinum (Cisplatin; CDDP) was observed in mice. However, the protective effect seems not always to correlate with metallothionein (MT) levels in the liver and kidney of mice treated with one of these metals, suggesting possible participation in this protection of mechanisms other than MT induction by the preadministered metals.

Animals↗
PubMedDate not supplied

Establishment and characterization of a cisplatin-resistant human neuroblastoma cell line.

BACKGROUND: To investigate the mechanisms of cisplatin (CDDP)-resistance in neuroblastoma(NB), we established a CDDP-resistant human NB cell line, BM1R2. MATERIALS AND METHODS: We characterized BM1R2 in terms of the susceptibilities to other anticancer agents, MDR1 and MRP expression, MYCN amplification, intracellular gultathione-S-transferase(GST-pi), metallothionein(MT) and gultathione(GSH) levels, and immunocytochemical and cytogenetic features. RESULTS: When compared to parent BM1 line, BM1R2 exhibited a 17.0-fold resistance to CDDP and cross-resistance to other agents. MRP expression was only observed in BM1R2, whereas MDR1 was expressed in both lines. Notably higher intracellular GST-pi and MT levels were observed in BM1R2 cells. MYCN amplifications were 50 and 6 copies in BM1 and BM1R2, respectively, and additional aberrations were observed in chromosome 1 and 2 in BM1R2. CONCLUSION: It was suggested that GST-pi and MT could exert crucial roles on CDDP-resistance in our system. BM1R2 is of great interest for investigating the mechanisms of CDDP-resistance in NB.

ATP Binding Cassette Transporter, Subfamily B, Mem↗