Impact of heavy metals on changes in metabolic biomarkers of carp fish, Cirrhinus mrigala

Abstract

The Indian Major carp fish, Cirrhinus mrigala were exposed to 1/10 th sub lethal concentration of three toxic heavy metals – Cadmium chloride (CdCl 2 ), Lead chloride (PbCl 2 ) and Mercuric Chloride (HgCl 2 ) for a period of 3, 7, 15, 30 and 45 days to study their effect on biochemical and metabolic enzyme biomarkers. The glycogen contents in gill, liver and muscle tissues of carp fish, Cirrhinus mrigala were found to be decreased. The maximum percentage decrease (65.57%) was observed on day 45 in liver tissue under mercuric chloride toxic stress. The succinate dehydrogenase (SDH), malate dehydrogenase (MDA), cytochrome C-oxidase and protein contents in three tissues were gradually decreased, whereas lactate dehydrogenase (LDH), aspartate amino transferase (AAT) and alanine transferase (AIAT) showed a constant and gradual elevation throughout the experimental period of 45 days under the treatment of heavy metals intoxicated fish. It is observed that the increased / decreased percentage was very much pronounced by HgCl 2 ) in liver tissue in particular. These variations have assumed that the fish yields high energy demands to overcome the stress indicated by the existence of hypoproteinamea in all tissues of fish. // //