Analysis of glutathione endpoints for measuring copper stress in <i>Chlamydomonas reinhardth</i>

Environmental Toxicology and Chemistry - Tập 26 Số 8 - Trang 1563-1571 - 2007
Tasha Stoiber1, Martin M. Shafer1,2, Dawn A. Karner Perkins2, Jocelyn D.C. Hemming2, David E. Armstrong1
1Environmental Chemistry and Technology Program, University of Wisconsin-Madison, 660 North Park Street, Madison, Wisconsin 53706, USA
2Wisconsin State Laboratory of Hygiene, 2601 Agriculture Drive, Madison, Wisconsin 53718, USA

Tóm tắt

AbstractGlutathione (GSH) is the most abundant nonprotein thiol in eukaryotic cells and it protects cells by functioning as an antioxidant and a metal‐binding ligand. Because glutathione readily undergoes oxidation‐reduction reactions to combat oxidative stress, intracellular ratios of the reduced (GSH) to the oxidized (GSSG) forms of glutathione may serve as an important biomarker of exposure and effect of trace metals in eukaryotic cells. We compared sensitivity of glutathione ratios in the freshwater alga Chlamydomonas reinhardtii to the traditional endpoints of cell growth rates and chlorophyll a following exposure to Cu for periods of 6 and 24 h. A response of the GSH:GSSG ratio to Cu concentration was observed at Cu levels of 40 and 80 nM after exposure for both 6 and 24 h. The concentration of total GSH at 24 h was roughly half the value at 6 h after exposure to either 40 or 80 nM Cu. A response for cell growth rate was observed only at 24 h, whereby the average specific growth rate decreased from about 1.1 to 0.4 d−1. The total Cu concentrations eliciting a cell response of 50%, effect concentrations (EC50s), after 24 h of exposure were similar (49.2, 49.8, and 38.2 nM Cu) and not significantly different for GSH:GSSG ratio, GSH levels, and specific growth, respectively. Total cell‐associated Cu concentrations after exposure for 24 h were calculated from the EC50 endpoints and ranged from 13.3 to 17.0 fg/cell. Overall, thiol ratios were indicative of toxicity resulting from exposure to Cu, but precision may be greater for the cell growth rate endpoints.

Từ khóa


Tài liệu tham khảo

10.1104/pp.98.3.853

10.1071/FP03129

10.1111/j.0022-3646.2003.02-193.x

10.1111/j.1365-3040.1990.tb01304.x

10.3354/meps232093

10.1046/j.1529-8817.2002.t01-1-01223.x

10.1073/pnas.86.18.6838

10.1093/jexbot/49.321.649

10.1016/S0168-9452(00)00392-7

10.4319/lo.2005.50.2.0516

10.4319/lo.2004.49.4.0991

10.4319/lo.1999.44.7.1750

10.1139/cjm-47-11-987

10.1023/A:1003502428466

10.1021/es0525051

10.1007/BF00214835

10.1007/s001289900626

10.1139/f04-129

Morel FMM, 1975, Description of the algal growth media “Aquil” and “Fraquil”

10.1016/0022-0981(88)90063-9

10.1080/01965581.1988.10749544

10.1046/j.1529-8817.1999.3520403.x

Guillard RRL, 1973, Handbook of Phycological Methods. Culture Methods and Growth Measurements, 69

Arar EJ, 1997, Method 445.0. In vitro determination of chlorophyll a and pheophytin a in marine and freshwater algae by fluorescence

10.1016/0003-2697(80)90139-6

10.1074/jbc.275.21.16289

10.1046/j.1365-3040.2003.01073.x

10.1021/es030669g

10.1002/etc.5620160218

10.1023/A:1006397714430

10.1897/05-214R.1

10.1104/pp.103.023424

10.1093/oxfordjournals.pcp.a077163

10.1021/es049256l

10.1897/02-418

10.1002/etc.5620210409

10.1007/s00216-004-2525-1

Thông tin
Thông tin xuất bản

Environmental Toxicology and Chemistry

Tập 26 Số 8

1563-1571

Thông tin tác giả