TY - JOUR
T1 - Zinc bioaccumulation and ionoregulatory impacts in Fundulus heteroclitus exposed to sublethal waterborne zinc at different salinities
AU - Loro, Vania Lucia
AU - Nogueira, Lygia
AU - Nadella, Sunita R.
AU - Wood, Chris M.
PY - 2014/11
Y1 - 2014/11
N2 - Exposure of Fundulus heteroclitus to an environmentally relevant Zn concentration (500 μg L- 1) at different salinities (0, 3.5, 10.5, and 35 ppt) revealed the following effects: (i) plasma [Zn] doubled after exposure at 0 ppt, a response which was eliminated at 35 ppt. Tissue [Zn] also increased in gill, liver, intestine, and carcass at 0 ppt. (ii) Both branchial and intestinal Ca2+ ATPase activities decreased in response to Zn at 0 ppt and were elevated at 35 ppt. Plasma [Ca] decreased by 50% at 0 ppt and by 30% at 3.5 ppt and increased by 20% at 35 ppt. Gill [Ca] decreased by 35% at 0 ppt and increased by about 30% at all higher salinities. (iii) Branchial Na +,K+ ATPase activity decreased by 50% at 0 ppt, increased by 30% and 90% at 10.5 and 35 ppt respectively. Intestinal Na+,K + ATPase activity was reduced by 30% at 0 ppt. (iv) Plasma [Na] decreased by 30% at 0 ppt in Zn-exposed. Zn exposure also disturbed the homeostasis of tissue cations (Na+, K+, Ca++, Mg++) in a tissue-specific and salinity-dependent manner. (v) Drinking rate was not altered by Zn exposure. In toxicity tests, acute Zn lethality (96-h LC50) increased in a close to linear fashion from 9.8 mg L - 1 at 0 ppt to 75.0 mg L - 1 at 35 ppt. We conclude that sublethal Zn exposure causes pathological changes in both Ca++ and Na+ homeostases, and that increasing salinity exerts protective effects against both sublethal and lethal Zn toxicities.
AB - Exposure of Fundulus heteroclitus to an environmentally relevant Zn concentration (500 μg L- 1) at different salinities (0, 3.5, 10.5, and 35 ppt) revealed the following effects: (i) plasma [Zn] doubled after exposure at 0 ppt, a response which was eliminated at 35 ppt. Tissue [Zn] also increased in gill, liver, intestine, and carcass at 0 ppt. (ii) Both branchial and intestinal Ca2+ ATPase activities decreased in response to Zn at 0 ppt and were elevated at 35 ppt. Plasma [Ca] decreased by 50% at 0 ppt and by 30% at 3.5 ppt and increased by 20% at 35 ppt. Gill [Ca] decreased by 35% at 0 ppt and increased by about 30% at all higher salinities. (iii) Branchial Na +,K+ ATPase activity decreased by 50% at 0 ppt, increased by 30% and 90% at 10.5 and 35 ppt respectively. Intestinal Na+,K + ATPase activity was reduced by 30% at 0 ppt. (iv) Plasma [Na] decreased by 30% at 0 ppt in Zn-exposed. Zn exposure also disturbed the homeostasis of tissue cations (Na+, K+, Ca++, Mg++) in a tissue-specific and salinity-dependent manner. (v) Drinking rate was not altered by Zn exposure. In toxicity tests, acute Zn lethality (96-h LC50) increased in a close to linear fashion from 9.8 mg L - 1 at 0 ppt to 75.0 mg L - 1 at 35 ppt. We conclude that sublethal Zn exposure causes pathological changes in both Ca++ and Na+ homeostases, and that increasing salinity exerts protective effects against both sublethal and lethal Zn toxicities.
KW - Calcium homeostasis
KW - Killifish
KW - Salinity
KW - Sodium homeostasis
KW - Zinc
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UR - http://www.scopus.com/inward/citedby.url?scp=84905670770&partnerID=8YFLogxK
U2 - 10.1016/j.cbpc.2014.07.004
DO - 10.1016/j.cbpc.2014.07.004
M3 - Article
C2 - 25051304
AN - SCOPUS:84905670770
VL - 166
SP - 96
EP - 104
JO - Comparative Biochemistry and Physiology Part - C: Toxicology and Pharmacology
JF - Comparative Biochemistry and Physiology Part - C: Toxicology and Pharmacology
SN - 1532-0456
ER -