effects of lead (heavy metal) on profile enzyme in some tissues and selection of acceptable indices of snow trout (schizothorax zarudnyi)

abstract pollution is a world problem with serious consequences. heavy metals are an important group of these contaminants and enter aquatic ecosystems from anthropogenic and natural sources and animal health and systems are affected. in this study, the effect of lead exposure (3 mg/l concentration, 30 days) on activity of tissue enzymes, including acetyl cholinesterase, alanine aminotransferase (alt), aspartate aminotransferase (ast), alkaline phosphatase (alp) and lactate dehydrogenase (ldh) in liver, gills, brain and muscle were studied in snow trout (schizothorax zarudnyi). the results showed that lead caused a significant inhibition of acetyl cholinesterase in the gills and brain as compared to control group (p˂0/05). the activity of alt was increased significantly in the liver and brain homogenates following lead acetate exposure (p˂0/05). a significant increase in ast activity was observed in the liver and brain (p˂0/05). moreover, ldh and alp activity were increased significantly following lead acetate exposure only in the liver (p˂0/05). according to this, lead exposure in snow trout leads to interactions between these metal and biological systems, which could affect metabolic enzyme activities in some tissues.the enzyme activity by lead did not follow the same pattern of increase or decrease and different results were based on enzymes and tissue. therefore, monitoring of enzymatic profiles in tissues of snow trout could be useful for identification of overall fish health and organ dysfunction following lead exposure.