بررسي تغييرات اولترامور فولوژيك فلزات سنگين كادميم ، مس و جيوه براسپرم با استفاده از ميكروسكوپ الكتروني

A STUDY OF THE UL TRAMORPHOLOGICAL CHANGES IN SPERMS EXPOSED TO CADMIUM, COPPER AND MERCURY USING AN ELECTRON MICROSCOPE

Introduction: Heavy metals pollution of various resources and human exposure to these result n various disorders. It has been reported that chronic exposure to heavy metals has an adverse effect on reproductive and sperm functions. Aquatic ecosystem pollution with heavy metals due to industrial activities and release of city sewages in rivers is one of the major concerns of societies. Heavy metals accumulate in the beds of rivers, lakes and seas and then enter the food chain and are finally absorbed by humans. When they accumulate in reproductive tissues, they can cause deleterious effects on spermatogenesis and sperm morphology. Material & Methods: This study has been performed to study the ultramorphological changes in sperms exposed to 3 heavy metals. Sperms were incubated with different concentrations of cadmium, copper and mercury for 3 hours and were then analyzed by a scanning electromicroscope (SEM). Results: The results showed that mercury was the most toxic heavy metal studied here and caused tail detachment and head condensation in sperms.Cadmium and copper exerted extensive morphological effects on sperms (mainly enlarging spermʹs head) and sperm decondensation. The results confirmed that part of heavy metals toxicity could be due to morphological changes and damaged sperms cannot swim freely and fertilize the ova. Conclusion: There was no difference in the sensitivity of the sperms of different varieties of fish towards the heavy metals.