BIOCHEMICAL AND NEUROENDOCRINOLOGICAL STUDIES ON THE EFFECT OF DELTAMETHRIN IN NORMAL AND INTOXICATED RATS

Abstract

Synthetic pyrethroids are worldwide insecticides which may have eurotoxic effects on behavioral, autonomi;,apd neuro-endocrine functions of mammals, including man. Pyrethroids are divided into two groups according to the poisoning symptoms in rats. Type I contains non-cyano group and type II contains an alpha cyano group in their chemical structures. The primary site of action of deltamethrin, one of the type II pyrethroids, was found to be within the central nervous system.

The aim of this study is the elucidation of the mechanism of action of deltamethrin. Since neurotransmitter synthesizing and degrading enzymes play a crucial roles in neuronal activity and normal physiological function by contributing to regulation of neurotransmitter levels, this study is extended to evaluate some neurotransmitter enzyme inhibitors as antidote for deltamethrin neurotoxicity. These enzyme inhibitors are the acetylcholinesterase (AChE) inhibitor, neostigmine; the tyrosine hydroxylase inhibitor, a-methyl tyrosine; and semicarbazide-sensitive amine oxidase (SSAO) inhibitor, semicarbazide HCI.

Adult male albino rats weighing 200-250 g were used in this study. Animals were divided into 8 groups (20 rats each). All enzyme inhibitors were administered intraperitoneally at 0 time as pretreatment and 30 min later, the deltamethrin. was also injected. Groups from 1 to 4 represent the negative and positive controls to investigate the effect of saline (0.9 %), neostigmine (0.4 mg I kg), methyl tyrosine (100 mg I kg), and semi carbazide (30 mg/kg) respectively. In deltamethrin-treated