Bioconcentration of zinc and its effect on the biochemical constituents of the gill tissues of Labeo rohita: An FT-IR study

In the present work, an attempt has been made to assess the bioconcentration and distribution of zinc on the selected organs of Labeo rohita and to study the effect of zinc exposure on the biochemical constitutions of gill tissues of L. rohita by using FT-IR Spectroscopy. The concentration pattern in the organs reveals that the liver is the prime site of metal binding and muscle accumulates least metal concentration. The accumulation profile is in the order: liver > gill > kidney > brain > bone > muscle. It has also been observed that the administration of chelating agent d-Penicillamine (DPA) reduces the zinc concentration in all tissues more effectively than the administration of the chelating agent Ethylene Diamine Tetra Acetic acid. The FT-IR spectra reveal that zinc exposure causes significant changes in the biochemical constitutions of the gill tissues. It causes an alteration in the protein secondary structures by decreasing the α-helix and increasing the β-sheet contents. Further, it has been observed that the administration of chelating agent DPA improves the protein and lipid contents in the gill tissues compared to zinc exposed tissues. This result shows that DPA is the effective chelator of zinc in reducing the body burden of L. rohita fingerlings. In conclusion, the findings of the current study suggest that zinc exposure causes significant changes in both lipids and proteins of the gill tissues, and changes the protein profile in favour of β-sheet structure.