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

5 DISCUSSION
5.1 Significance of the experimental procedures
Rats were treated orally with graded doses of TCDD and the effects were seen
on various parameters of male reproductive functions. In order to see the effects of
vitamin E on TCDD-induced alterations in the testis and epididymis the rats were
administered with vitamin E along with TCDD.
5.1.1 Experimental treatments
TCDD is one of the most potent environmental contaminants, which has been
shown to alter male reproduction of rats causing reduced fertility. In the present study
TCDD (1, 10 and 100 ngi Kg body weight) day) was administered orally to 45 days
old male rats for 45 days in order to see the effects of subchronic exposure of TCDD
on functional aspects of male reproduction. In the subchronic toxicity test with rats
exposure usually begins at 6 to 8 weeks of age (US Environmental Protection Agency,
1998). Rats at postnatal day 45 have been reported to be at the threshold of puberty
where the first spermatozoa are seen in the lumen of the seminiferous tubules
(Clermont and Perey, 1957). The duration of the whole process of spermatogenic
cycle in male rats is approximately 45 days (Clermont and Perey, 1957). In the
present studies rats were treated from puberty to adulthood through a complete
spermatogenic cycle. TCDD was administered orally because most of the
environmental contaminants enter into the body through this route.
For standardization of doses, rats were treated with seven different doses of
TCDD for 45 days. The doses ranged from 0 to 1000 ng/ Kg body weight/ day and 3
animals were used for each dose. The body weight gains were recorded for 45-days.
Administration of TCDD at the dose levels of 0 to 100 ng/ Kg body weighti day for
45 days did not show any significant changes in the body weight (Fig. 2 & 3).
However, adminiseation of TCDD at higher doses decreased body weight of the