SEASONAL VARIATIONS OF BIOCHEMICAL MARKERS IN TWO SPECIES OF MOLLUSCS AS INDICATION OF HEAVY METALS POLLUTION

I.J.A.B.R, VOL. 3(3) 2013: Galley proof ISSN 2250 – 3579
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SEASONAL VARIATIONS OF BIOCHEMICAL MARKERS IN TWO SPECIES OF MOLLUSCS AS INDICATION OF HEAVY METALS POLLUTION
1Jasim M. Salman, 1Ayad M. J. Al-mamoori, 1Randall Hughes A. & 2Ali Hmood AL-Saadi
*College of science, Babylon University, Iraq
**Florida State University, U.S.A
ABSTRACT
This investigation was designed to study the seasonal variation of biochemical markers (Total protein, Vitamin C, Vitamin E, Acetylcholinesterase and Metallothioneins ) in two species of Molluscs(Viviparus bengalensis and Corbicula fluminea from two sites of Al-Hilla river, the results have recorded seasonal variations of totalprotein (17.2,11.9mg/g),Vitamin C (6.8,7.2?g/mg),VitaminE(11.8,12.1?g/mg),Acetylcholinesterase(48.3,50.3nmol/min./mg), and Metallothionein (53.8, 42.3 ?g/g) in snail & Clam respectively with highest concentration in digestive gland than gills. The highest values for all biochemical markers have recorded during spring and summer season 2011.
KEY WORDS: Biochemical markers, Seasonal variations, heavy metals , Total protein, Acetylcholinesterase, Vitamins, Metallothioneins
INTRODUCTION
Heavy metals have complex spectra, form colored salts and double salts, and they have been shown to produce marked toxicity at the target sites, and effect on DNA, which is the carrier of inherited information and any gross change in its structure potentially, indicates serious biological changes, Biomarkers as predictive of advanced toxicity at higher biological levels and using comes from their sensitivity and specificity to pollutants and also for ideal reasons such as the cost and time associated with with measuring a stress response ( Conners , 2004). Vitamin C is a water-soluble vitamin. Like vitamin E, it is an effective antioxidant. Vitamin C can protect essential substances in the body such as proteins, lipids, carbohydrates, DNA and RNA from damage by free radicals (Padayatty etal., 2003 ). Metallothioneins constitutes an important binding protein with low molecular weight (6-7) KDa and high cysteine content (>30%) which play an important role in detoxification of toxic chemicals and have a role in the maintenance of homeostasis of essential metals and used as biomarkers to assess the toxicity of pollutants ( Huang etal., 2007), Acetylcholinesterase is old biomarker may be responding to low level of pollution in the environment (Bouldin etal., 2007) and are considered as unique enzyme whose physiological function to remove acetylcholine from synaptic clefts. Biomarkers can be considered as early defense response for heavy metals impact , So (Bigo etal., 2011) measured the early effects of copper (10 and 50 lg L21), cadmium (2, 10, and 50 lg L21) and mixtures of these metals in the freshwater bivalve Corbicula fluminea exposed for 12 h in laboratory, Measurement of acetylcholinesterase (AChE) is broadly used like present study as biomarker of pollution, AChE activity was
monitored in the clam Tapes philippinarum in the Lagoon of Venice (Italy) by (Matozzo et al., 2005), no particular correlation between AChE activity and Condition Index (CI) was found, and marked differences in AChE activity were showed when comparing enzyme activity of clams from various sites in the Lagoon of Venice.
MATERIALS & METHODS
Snail and clam samples were collected seasonally by using plastic bag and when brought to laboratory, they were washed with tap water and Distilled water to remove any residue to make direct and suitable analyses, Protein concentration was estimated according to method of Bradford (1976), Vitamin C is present in both a reduced form ascorbic acid (AsA) and an oxidized form (dehydroascorbic acid (DHAsA), this method measures total vitamin C (i.e., AsA + DHAsA), and according to (Omaye et al., 1979) , (Burtis & Ashwood, 1999). Vitamin E was determined according to (Quaife etal., 1949) which includes Emmerie and Engel color reaction with ferric chloride and ?,?--dipyridyl to give a red color, Metallothionein was determined by evaluating the sulphyhydryl (-SH) residue content according to method of Ellman (1958) and (Viarengo etal., 1997). Anew and rapid colorimetric determination was adapted to calculate the Acetylcholinesterase activity in Molluscs according to method descirbed by Ellman et al.( 1961).