Testicular blood flow and microcirculation in rats after treatment with ethane dimethyl sulfonate

The effects of ethane dimethyl sulfonate (EDS) on total testicular blood flow, microcirculation, and the testicular interstitial fluid volume (IFV) in rats were studied. In agreement with previous studies, treatment of control rats with human chorionic gonadotropin (hCG) induced an increase in IFV and total testicular blood flow as measured with radioactive microspheres. These effects of hCG were completely abolished in rats pretreated with EDS; in EDS-treated rats not receiving any hCG, there were decreases in IFV when compared with untreated control rats. Furthermore, the pulsatile pattern of testicular microcirculation registered with laser-Doppler flowmetry was abolished after EDS treatment, and this effect was not influenced by hCG treatment. The hCG-induced increase in IFV is associated with an increased accumulation of polymorphonuclear leukocytes locally in the testis, but this accumulation of leukocytes was not observed in rats pretreated with EDS. It was concluded from the present study that hCG-induced changes in total testicular blood flow and testicular microcirculation require functionally intact Leydig cells.