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

lilnction is to ililcrccpt lipid pcroxyl rudiouls and thcrchy tcr~lii~l~tc lipid pc~.oxid;~livo
chain reactions.
The free radical clearing ability of u-tocopherol is due to
delocalisation of an unpaired electron in its conjugated double bond system. The
observed reduction in the levels of antioxidants in the testis of rats treated with TCDD
might be due reduced recycling of antioxidants in tissues.
Oxidative stress induced by TCDD has been shown to occur primarily in the
mitochondria followed by microsome-rich fractions (Latchoumycandane el a/.,
2002~). Decreased activities of antioxidant enzymes and increased level of lipid
peroxidation in the mitochondrial and rnicrosomal fractions have been reported in the
testis of rats following TCDD treatments (Latchoumycandane el a[., 2002~).
5.2.8 Effect of TCDD on antioxidant system in the epididymal sperm
Administration of TCDD increased the production of superoxide anion, nitric
oxide and hydrogen peroxide in the epididymal sperm of rats when compared to the
corresponding groups of control animals (Fig. 14a to 14c; Table 11). Administration
of TCDD decreased the level of antioxidants such as glutathione and a-tocopherol in
the epididyrnal sperm of rats (Fig. 1 Sa & 15b; Table 12). Administration of TCDD
decreased the activities of superoxide dismutase, catalase, glutathione reductase and
glutathione peroxidax (Fig. 16a to 16d: Table 13) while the level of lipid
peroxidation increased significantly in the epididymal sperm of rats as compared to
the corresponding groups of control animals (Fig. 17; Table 13).
TCDD has been shown to increase the production of reactive oxygen species
in the epididymal sperm of rats (Latcho~~~iiycand;~nc ct 111.. 2002h). Incrcilscd
production of supcroxide anion nnd hydrogen pcroxidc in the cpididymul hpcrtn ct~uld
reflect the adverse effect of TCDD 011 the generation of reactive oxygen species. l'he
observed reduction in the level of glutathione and u-tocopherol reflect adverse effect
of TCDD on the antioxidants in the epididymal sperm of nts. Reduction in the
activities of antioxidant enzymes and increased levels of lipid peroxidation in the
epididyrnal sperm has already been reported following TCDD treatment