ABSTRACTThe causes of poor semen quality following spinal cord injury (SCI) are unknown. One possible mechanism is decreased testicular blood flow. Chronic testicular ischemia in non-SCI animals has been shown to have significant adverse impact on spermatogenesis. This study was designed to evaluate testicular blood flow following SCI in the Sprague Dawley rat. Testicular blood flows were determined in 11 rats with SCI at thoracic level nine (T9) and six sham control rats three days prior and three days and 14 days after SCI. Testicular blood flow velocity was measured with a Doppler flow probe. Blood flows were compared between groups using T-tests. There were no significant changes in blood flow in the sham operated rats three or 14 days after surgery. However, three days after SCI, blood flow had decreased in the SCI rats to 78±5 percent of the pre-SCI flow (t =-4.65 with 10 df, p<0.001). At 14 days after SCI, blood flow was still decreased to 77+8 percent, (t =-3.40 with 3 df, p<0.05). This study established that following SCI, testicular blood flow decreases in the Sprague Dawley rat.(J Spinal Cord/Wed; 19:183–185)