Effects of Lead and Selenium Interaction on Acetylcholinesterase Activity in Brain and Accumulation of Metal in Tissues of Oreochromis niloticus (L., 1758)

Gülsemin Şen,Sahire Karaytuğ

doi:10.28978/nesciences.328857

Abstract

The potential accumulation of lead in different tissues of Oreochromis niloticus and the effects of selenium in AChE inhibition caused by lead in brain were investigated. Juvenile O. niloticus samples were exposed to combination of 1 mg L-1 and 2 mg L-1 lead and 1mg L-1 lead+2mg L-1 selenium and 2mg L-1 lead+4mg L-1 selenium for 1, 7 and 15 days respectively. The accumulation of lead in gill, brain, liver and muscle tissues was analyzed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) as well as brain acetylcholinesterase (AChE, E.C.3.1.1.7) enzyme activity was also analyzed by spectrophotometric method. No mortality was observed during lead exposure in relation to time period and exposed concentrations. Lead accumulation was occurred in all tissues in relation to time. Maximum lead accumulation occurred in brain tissue, followed by the liver, gills and muscle tissues in relation to time period. Selenium caused a decrease on accumulation of lead in tissues (all selenium mixtures in muscle tissue on the first day, 1mg L-1 Pb+2mg L-1 selenium in gill tissue on the seventh day, in liver tissue on the seventh day except 2mg L-1 Pb+4mg L-1 selenium mixtures) at the end of each of all three test periods. Inhibition of AChE activity was caused by the highest concentration and by the short-term effect of lead. Such effect of lead was eliminated by selenium mixture. Lead and selenium mixture were resulted an increase in activity on 15th day at the highest concentration. Selenium led to decrease in the accumulation of lead in the tissues and caused to improvement in the loss of AChE activity.

Highlights

Having learned to process copper in the Stone Age, man kept dealing with various metals over time; on the one hand he has been affected by them, and started to pollute his environment
This study aims to evaluate the impact of accumulation potential of lead in different tissues in O. niloticus, and the impact of selenium on the brain AChE enzyme inhibition caused by lead during a period of 1, 7 through 15 days
Pb accumulation has been determined mostly in brain tissues in all attempted processes and it has been followed by liver, gill and muscle tissues

Summary

Introduction

Having learned to process copper in the Stone Age, man kept dealing with various metals over time; on the one hand he has been affected by them, and started to pollute his environment. Modern agricultural applications, increasing number of industrial businesses caused excess accumulation of heavy metals in aquatic environments (Kalay et al, 2003). Heavy metals are known for their serious potentials to pollute the environment due to their presence in the environment and their being accumulated by aquatic organisms. The organisms are negatively affected by the increased level of heavy metals in aquatic habitats (Çoğun & Kargın, 2013). Lead (Pb) has no metabolic effect but organisms are exposed to it in all environments. Presenting a chemical similarity to calcium, it is processed with calcium, attached to bone tissue. It has been shown that lead enters neuronal intracellular environment (Bressler & Goldstein, 1991)

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