ON TESTIS AND EPlDlDYMlS OF RATS - Pondicherry University ...

have also been reported in the rats administered with estrogenic organochlori~lc
pesticides, lindane and methoxychlor (Sujatha e! a[., 2001: Chitra el al., 2001;
Latchoumycandane et al., 2002a. b). Methoxychlor has been reported to induce
oxidative stress in mitochondrial and microsome-rich fractions of rat testis
(Latchoumycandane and Mathur, 2002).
1.3.1 23,7,8-Tctmchlorodibenzo-pain (TCDD)
2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD), prototypical member of
halogenated aromatic hydrocarbons, is one of the polychlorinated dibenzo-p-dioxins
which arc formed as by-products in a number of industrial processes and during
combustion of indusmal waste. TCDD has been identified as an environmental
contaminant in the production of chlorinated phenols and their derived products as
well as other chlorinated industrial compounds. These compounds have also been
detected as by-products in sewage sludge, pulp and paper mill effluents. in diverse
high-temperature industrial processes, and by-products of incineration of diverse
organic materials including wood and coal. TCDD is stable to both chemical and
thermal degradation and this stability contributes to its persistence in the environment.
This compound is also lipophilic and environmental residues preferentially
bioaccumulate in the food chain and is routinely detected in fish, wildlife. human
adipose tissue, serum and milk (Rappe, 1991). The widespread human exposure and
environmental contamination of TCDD has spurred research on the biochemical and
toxic responses and mechanism of action elicited in animal models, mammalian cells
in culture and in exposed human populations.
TCDD is one of the most toxic members of polychlorinated dibenzo-p-dioxins
and has been extensively used as a prototype to investigate various activities of thesc
compounds and their m~rhanism 01' action (1.ucic.r o (11.. 1093; Sak. IOVS). I'hc
diverse spectmm of biochemical and toxic responses elicited by TCDD and related
compounds include a wasting syndrome. immunosuppression. hepatotoxicity and
porphyria, carcinogenic and anticarcinoge-dc activities, hypo- and hyperplastic