Nahid Syahmard - Kazeroon Center Applied Science University, Fars, Iran.

Background and objective : Every year lots of different pesticides through various ways goto the environment . These pesticides are distributed to the environment and transported to theremote areas . To predict the effects of these substances on the ecosystem, in addition toinformation on their toxicity, how to enter, play and behavior of these compounds in natureshould be well known . The purpose of this study was to determine the effect of oxy dymtonmethyl toxin on body weight changes and testis tissue changes in rats .Materials and Methods : For this purpose, ۴۰ adult male Wistar rats, weighing approximately۱۹۰ ۱۰ gr were divided into ۵ groups of ۸ . The groups include : Control group , sham andtreatment with doses ۲ppm , ۵ppm , ۱۰ppm . Toxin was fed to the animals orally daily for ۱۴ days. At the end of experimental period , animals were weighed , and animal’s testis for examining oftissue changes removed from body and weighed and after the tissue sections were prepared andstained with hematoxylin – eosin, they were studied and examined .Results : This toxin in any of levels does not make significant effect on body weight andtesticular weight of animals . Histological studies showed that treatment group with maximumamount of toxin has decrease of sperm density compared with control group P<۰.۰۵ .Conclusion : Probably this toxin with effect on hormone testosterone and secretion decrease ofthis hormone causes weight decrease and also testis tissue changes specially in high doses of toxin

Oxy dymton methyl , Body weight , Testis tissue , Male rat