Sulfhydryl systems are a critical factor in the zebrafish developmental toxicity of the dithiocarbamate sodium metam (NaM).

TitleSulfhydryl systems are a critical factor in the zebrafish developmental toxicity of the dithiocarbamate sodium metam (NaM).
Publication TypeJournal Article
Year of Publication2008
AuthorsTilton, F, La Du, JK, Tanguay, RL
JournalAquat Toxicol
Date Published2008 Nov 11
KeywordsAnimals, Antioxidants, Embryo, Nonmammalian, Glutathione, Sulfhydryl Compounds, Thiocarbamates, Toxicity Tests, Water Pollutants, Chemical, Zebrafish

Dithiocarbamates (DTCs) are sulfhydryls (thiol)-containing compounds, often associated with metals, and have both antioxidant and pro-oxidant abilities depending on the compound, experimental system and condition. In this study we investigated whether cell death plays a role in the manifestation of DTC-induced notochord distortions in the developing zebrafish and if thiol-containing compounds or antioxidants could modify this developmental toxicity. Sodium metam (NaM) induced notochord distortions could not be protected with the antioxidants ascorbic acid, trolox (synthetic vitamin E) or lipoic acid. However, NaM-induced distortions could be protected with co-exposure to glutathione or N-Acetyl Cysteine. Staggering the NaM and glutathione exposures in consecutive 10h developmental windows also resulted in protection. There were no discernable changes in TUNEL positive cells, a marker of apoptotic cells, at 24h post-fertilization (hpf) in NaM, dimethyl-dithiocarbamate, carbon disulfide, or neocuproine exposed embryos. Live NaM-exposed embryos incubated with acridine orange, a general stain for cell death, for 1h beginning at 11, 18 and 24hpf showed clusters of stained nuclei near the somitogenic front but not in the cells making up the notochord. Overall, induction of apoptotic pathways and widespread cell death are not involved in the manifestation of the adverse developmental outcomes following NaM exposure. However, cellular thiol status or critical sulfhydryl moieties are important considerations in the mechanisms of DTC developmental toxicity.

Alternate JournalAquat. Toxicol.
PubMed ID18823668
PubMed Central IDPMC3270488
Grant ListP30 ES000210 / ES / NIEHS NIH HHS / United States
P30 ES000210-36 / ES / NIEHS NIH HHS / United States