Experimental testicular torsion: reperfusion blood flow and subsequent testicular venous plasma testosterone concentrations.

OBJECTIVES: To examine the effect of torsion on subsequent testicular venous plasma testosterone concentrations (TVT) and to determine the relationship between the TVT values 30 days after torsion repair and testicular reperfusion immediately after torsion repair, because testicular torsion followed by repair induces an ischemia/reperfusion injury of the testis.
METHODS: Adult male rats were subjected to 1 hour of 720 degrees testicular torsion, a time and degree of torsion that has been shown to cause severe impairment of spermatogenesis. Testicular microvascular perfusion before torsion, during torsion, and 5 minutes after torsion repair was determined by laser Doppler flowmetry. The animals were evaluated 3 days and 30 days later for microvascular perfusion and TVT.
RESULTS: Experimental torsion significantly reduced testicular vascular perfusion. Five minutes after torsion repair, the mean flow values had returned to approximately 70% of the pretorsion values. Testicular torsion significantly reduced TVT at both 3 and 30 days after torsion repair. TVT 30 days after torsion repair was significantly, but inversely, related to reperfusion values immediately after torsion repair.
CONCLUSIONS: These results demonstrate that the minimal duration and degree of torsion known to cause loss of spermatogenesis in the rat also causes a significant reduction in testicular androgen production in the long term. This effect was inversely related to the reperfusion values immediately after torsion repair. This suggests that reperfusion/oxidative stress may play a role in Leydig cell dysfunction, as well as by acting directly in germ cell apoptosis.