| Title | ASSOCIATION OF METALS (MERCURY, CADMIUM AND ZINC) WITH METALLOTHIONEIN-LIKE PROTEINS IN STORAGE ORGANS OF STRANDED DOLPHINS FROM THE MEDITERRANEAN SEA (SOUTHERN ITALY) |
| Abstract | Selected toxic and essential metals (mercury, Hg; cadmium, Cd; and zinc, Zn) were determined in the liver and
in the kidney collected from 13 dolphins (Stenella coeruleoalba and Tursiops truncatus) stranded along the
southern coasts of Italy from 1991 to 1999. Liver samples were also analysed for their methyl mercury (MeHg)
and selenium (Se) contents. For subcellular fractionation, liver and kidney samples were homogenized in
Tris-HCl buffer; after centrifugation, the supernatant (cytosol) was separated from pellets (insoluble fraction),
heated at 80 uC for 10 min and centrifuged in order to separate the precipitate containing the thermolabile high
molecular weight proteins. The cytosol heat-stable fraction, including metallothionein-like proteins (MTLPs),
was then purified by gel filtration chromatography on Sephadex G-75 column. The three subcellular fractions
collected (insoluble fraction, thermolabile fraction and purified heat-stable fraction) were analysed for their Hg,
Cd and Zn contents. The analytical results confirm previous similar studies on toothed whales in showing that:
(1) in the liver, as well as in the kidney, Hg was mainly found in the insoluble fraction, therefore,
metallothioneins seem to have no role in the Hg detoxification; (2) in the liver, the molar ratio between Se and
inorganic Hg was very close to 1; this suggests that the final compound of MeHg detoxification could be HgSe
(tiemannite); (3) in almost all the samples, Cd and Zn were detected in the purified heat-stable fraction
(including MTLPs). The mechanism of Cd detoxification and Zn homeostasis is also discussed. |
| Source | Journal of environmental monitoring (Print) 6 (4), pp. 361–367 |
| Keywords | Heavy metalsmetallothionein-like proteinsstranded dolphinsMediterranean sea. |
| Journal | Journal of environmental monitoring (Print) |
| Editor | Royal Society of Chemistry,, Cambridge, Regno Unito |
| Year | 2004 |
| Type | Articolo in rivista |
| DOI | 10.1039/b315685k |
| Authors | A., Decataldo, A., Di Leo, S., Giandomenico and N., Cardellicchio |
| Text | 6534 2004 10.1039/b315685k ISI Web of Science WOS 000220529600019 Heavy metals metallothionein like proteins stranded dolphins Mediterranean sea. ASSOCIATION OF METALS MERCURY, CADMIUM AND ZINC WITH METALLOTHIONEIN LIKE PROTEINS IN STORAGE ORGANS OF STRANDED DOLPHINS FROM THE MEDITERRANEAN SEA SOUTHERN ITALY A., Decataldo, A., Di Leo, S., Giandomenico and N., Cardellicchio CNR, Istituto per l Ambiente Marino Costiero, Taranto Selected toxic and essential metals mercury, Hg; cadmium, Cd; and zinc, Zn were determined in the liver and in the kidney collected from 13 dolphins Stenella coeruleoalba and Tursiops truncatus stranded along the southern coasts of Italy from 1991 to 1999. Liver samples were also analysed for their methyl mercury MeHg and selenium Se contents. For subcellular fractionation, liver and kidney samples were homogenized in Tris HCl buffer; after centrifugation, the supernatant cytosol was separated from pellets insoluble fraction , heated at 80 uC for 10 min and centrifuged in order to separate the precipitate containing the thermolabile high molecular weight proteins. The cytosol heat stable fraction, including metallothionein like proteins MTLPs , was then purified by gel filtration chromatography on Sephadex G 75 column. The three subcellular fractions collected insoluble fraction, thermolabile fraction and purified heat stable fraction were analysed for their Hg, Cd and Zn contents. The analytical results confirm previous similar studies on toothed whales in showing that 1 in the liver, as well as in the kidney, Hg was mainly found in the insoluble fraction, therefore, metallothioneins seem to have no role in the Hg detoxification; 2 in the liver, the molar ratio between Se and inorganic Hg was very close to 1; this suggests that the final compound of MeHg detoxification could be HgSe tiemannite ; 3 in almost all the samples, Cd and Zn were detected in the purified heat stable fraction including MTLPs . The mechanism of Cd detoxification and Zn homeostasis is also discussed. 6 http //www.rsc.org/publishing/journals/EM/about.asp Rivista Internazionale Rivista internazionale con IF JEM 0.pdf Articolo in rivista Royal Society of Chemistry, 1464 0325 Journal of environmental monitoring Print Journal of environmental monitoring Print J. environ. monit. Print Journal of environmental monitoring Print JEM Cambridge. Print Print antonella.dileo DI LEO ANTONELLA santina.giandomenico GIANDOMENICO SANTINA nicola.cardellicchio CARDELLICCHIO NICOLA TA.P04.002.001 Fascia Costiera e Ambienti di Transizione analisi strutturale e funzionale delle componenti biotiche ed abiotiche degli ecosistemi per lo sviluppo sostenibile delle attivita |
