QUANTITATIVE AND STRUCTURAL CHANGES OF TESTIS AND SEMEN QUALITY PARAMETERS CHANGES CAUSED BY PERORAL ADMINISTRATION OF DIAZINON IN RATS

The aim of this study was to find the quantitative and structural changes in the rat testis and changes of semen quality after a diazinon administration. METHODS: Rats received diazinon (99% purity) in thier drinking water (40 mg .l -1 ) with free access. Age of rats at the beginning of the experiment was 30 days and experiment lasted for next 90 days. The histological samples were evaluated by histological and morphometric methods in light microscopy and the samples of semen were evaluated with CASA method. RESULTS: Disintergation of cellular associations in the seminiferous epithelium, germ cells evacuation into the tubule lumen and thier necrosis were mostly observed. Rarely vacuolisation and cracks of epithelium and fibrotisation of interstitial tissue were noted. Morphometric methods have shown extension of epithelium (P<0,01), reduction of  tubule lumen (P<0,001) and dilatation of blood vessels (P<0,001). In CASA analysis elevation of all parameters were noted, with statistically significant increase of DSL, VSL, ALH. Dilatation of blood vessels will be probably one of the most significant finding in diazinon toxicity because changes in blood flow in the testis are the key factors of accurate physiological function of testis. The epithelium despite the serious disintegration of germ cells associations and release of these necrotised germ cells to the lumen was significantly extended. This fact indicates the self-reparation compensational function. The same tendency (stimulation effects) has been found in all analysed sperm parameters. It supports previous hypothesis. CONCLUSIONS: Diazinon in this design of experiment causes the disintegration of the germinal epithelium cells associations consequently leading to necrosis and release of these cells to the tubule lumen. Dilatation of blood vessels and unknown stimulation effect on sperm quality parameters are two other common effects of diazinon. We concluded that diazinon in our subchronic low dose test causes middle to moderate histological,  morphometric and semen quality changes which were partially compensated with some unknown recovery mechanism. Otherwise, subcellular structures and their functions may be damaged which can lead to subfertility. Further investigation of diazinon is needed for verification of our hypothesis. doi:10.5219/188