eltamethrin is a synthetic compound that modulates sodium channels in the nerve cell membrane. This compound can keep the Na+ channels in an open state for a long time resulting to hyperactivity of the nervous system in mammals and insects. Deltamethrin can increase neurotransmitter release which is associated with elevated levels of intrasynaptosomal free Ca2+ and protein phosphorylation activities. Research shows that in the presence of increasing concentrations of deltamethrin, mRNA levels of IGF-I, IGF-II and GH-I significantly decreased in rainbow trout. Deltamethrin is an inhibitor of PP2.