Abstract:
Paraquat, a broad-spectrum plant killer is widely used in Sri Lanka despite its harmful
effects on living organisms. The aim of the present study was to investigate effects of Paraquat
on epididymal sperm structure and function of male rats. M ature rats (maintained in stand ard animal house conditions) were gavaged either with 10, 20 & 40 mg /kg body weight of
Paraquat (n=10 / group) or with the vehicle (distilled water, n= 10), for 3 successive days.
Treated males were paired individuals with pro-oestrous females on day 6 and total sperm
counts in epididymis were determined on day 7. Nuclear integrity of sperm DNA and ab normalities in sperm morphology (using separate sperm smears) were determined on the
day 7 using Acridine orange test. Pregnant females were laprotamised on day 14 and as sessed the pre-implantation loss. Live number of pups and their weights were determined at
the end of gestation period. Treatment caused a significant (P<0.05) reduction in total epidi dymal sperm count and sperm motility (reduction was marked in the lowest dose). In addi tion, results also showed a significant increase in pre implantation loss in all the treated
groups. A significant (P<0.05) damage to DNA integrity of sperm from caput region of rats
treated with 20 mg Paraquat/kg was significant and prominent in all the treatments. Sperm
abnormalities were mainly concentrated on sperm tail. The data suggest that low acute
concentrations of parquat can affect the sperm structure and function of male rats. Sperm
retains in cauda epididymis for at least 7 days in the rat and since the animals were killed on
day 7, observed pre-implantation loss possibly may due to any damage mediated through
the epididymis. Present study confirms that acute exposure of Paraquat can alter epididy mal sperm function of male rats.
