Williams, G and Snow, ET and West, JM, Exposure to As(III) and As(V) changes the Ca2+-activation properties of the two major fibre types from the chelae of the freshwater crustacean Cherax destructor, Aquatic Toxicology, 155 pp. 119-128. ISSN 0166-445X (2014) [Refereed Article]
Copyright 2014 Elsevier B.V.
Arsenic is a known carcinogen found in the soil in gold mining regions at concentrations thousands of times greater than gold. Mining releases arsenic into the environment and surrounding water bodies. The main chemical forms of arsenic found in the environment are inorganic arsenite (As(III)) and arsenate (As(V)). Yabbies (Cherax destructor) accumulate arsenic at levels comparable to those in the sediment of their environment but the effect on their physiological function is not known. The effects of arsenic exposure (10 ppm sodium arsenite, AsNaO2 – 5.7 ppm As(III)) and 10 ppm arsenic acid, Na2HAsO4·7H2O – 2.6 ppm As(V)) for 40 days on the contractile function of the two major fibre types from the chelae were determined. After exposure, individual fibres were isolated from the chela, "skinned" (membrane removed) and attached to the force recording apparatus. Contraction was induced in solutions containing increasing [Ca2+] until a maximum Ca2+-activation was obtained. Submaximal force responses were plotted as a percentage of the maximum Ca2+-activated force.
As(V) exposure resulted in lower levels of calcium required for activation than As(III) indicating an increased sensitivity to Ca2+ after long term exposure to arsenate compared to arsenite. Myosin heavy chain and tropomyosin content in individual fibres was also decreased as a result of arsenic exposure. Single fibres exposed to As(V) produced significantly more force than muscle fibres from control animals. Long-term exposure of yabbies to arsenic alters the contractile function of the two major fibre types in the chelae.
|Item Type:||Refereed Article|
|Keywords:||arsenic, yabbie, muscle physiology, environmental toxicology, As(III), As(V), skinned fibre, crustacean muscle, Ca2+-activationa|
|Research Division:||Medical and Health Sciences|
|Research Group:||Pharmacology and Pharmaceutical Sciences|
|Research Field:||Toxicology (incl. Clinical Toxicology)|
|Objective Group:||Public Health (excl. Specific Population Health)|
|Objective Field:||Environmental Health|
|Author:||Snow, ET (Associate Professor Elizabeth Snow)|
|Web of Science® Times Cited:||1|
|Deposited By:||Health Sciences A|
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