AN INVESTIGATION OF THE TOXICITY OF LINDANE IN VIVO AND IN VITRO
AN INVESTIGATION OF THE TOXICITY OF LINDANE IN VIVO AND IN VITRO
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Date
1997-09
Authors
BABAYE, YUSUF
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Abstract
The goal of this project is to study in vivo and in vitro, the mode of toxicity of
lindane (an organochlorine insecticide) at tissue/cellular level with the hope diat the
information obtained would provide an insight into the non-target toxicity of the
compound.
The in vivo investigation involved acute and chronic toxicity studies. In the acute
toxicity studies, the median lethal dose (LD50) of lindane using the intraperitoneal
(I.P.) route was determined as 25.4 mg/kg. The symptoms of toxicity were scored and
were found to be dose-dependant and mainly those of central nervous system (CNS).
In the chronic toxicity studies, results of the histopathological examination of
sections of the rat brain exposed to feeds contaminated with lindane indicated lesions
of different structures. There was vacuolations, necrosis of the oligodendroglial cells
and some degree of neuronal degeneration especially in the brain of rats exposed to the
contaminated feeds for a long period of time (4 to 12 weeks).
Electroencephalographic (EEG) pattern of rats fed on contaminated feeds
showed some degree of desynchronisation as compared to the control. The effect was
found to increase with dose and time of exposure. Since desynchronisation of EEG
pattern is associated with increased CNS activity, it is possible that chronic exposure
to lindane may produce symptoms of CNS stimulation.
The in vitro investigation was aimed at evaluating the role of sodium ions (Na+)
in the neurotoxicity of lindane. It was found that lindane dose-dependently attenuated
the effect of lignocaine (P< 0.001) on both the rabbit ileum and phrenic nerve
preparations. It was suggested that lindane increases the permeability of the membrane
to Na+ thereby interfering with the generation and propagation of action potential.
The importance of identifying the mechanism by which various chemicals
produce their toxicity cannot be overemphasized; in order to design a rational basis for
treatment and to make available adequate information necessary in the prevention,
diagnosis and management of intoxication.
Description
A Thesis in the Department of Pharmacology and Clinical Pharmacy
Submitted to the Postgraduate School
in partial fulfillment of the requirements for the Degree of
Master of Science in Pharmacology
Ahmadu Bello University, Zaria - Nigeria
Keywords
INVESTIGATION,, TOXICITY,, LINDANE,, VIVO,, VITRO