A comparison between the effect of sub-lethal doses of atrazine and DDT on brain and plasma acetylcholinesterase of the African catfish (Clarias gariepinus)‎

الملخص EN

The effect of in vivo exposure to two sublethal concentrations of atrazine and one concentration of DDT on acetylcholinesterase in brain and plasma of the fresh water fish Clarias gariepinus was measured.

Blood and brain were taken after various periods of exposure (3-168 hr for atrazine and 3-24 hr for DDT).

Controls were treated parallel.

A real inhibition of brain AChE specific activity was detected by exposure hr 6 at the lower atrazine concentration and by exposure hr 9 at the higher concentration.

The remainder of changes were considered false due to changes in brain water content and/or protein content.

The effect of DDT was restricted to a real activation only by exposure hr 6.

Plasma AChE specific activity increased throughout the whole experimental time during exposure to the lower concentration of atrazine, while reduction was recorded in the beginning and toward the end of experiment at the higher concentration.

Plasma AChE activity during DDT exposure ranged from initial decrease followed by increase, then inhibition and finally activation which could give an indication that DDT is more harmful than atrazine at its higher concentration (500 n-g/1).

Although the changes are clear in the enzyme activity of the brain, plasrfia AChE seems to be more useful as a monitor of exposure to anticholinesterase chemicals.