title: Acute spermatic cord torsion alters the microcirculation of the contralateral testis.
abstract: OBJECTIVE
  The purpose of this study was to characterize the hemodynamic changes in the contralateral testis during acute spermatic cord torsion in anesthetized rats.
  
  
  METHODS
  We used videomicroscopy to examine the microcirculation of the contralateral testis following acute torsion. Specifically, we examined the effect on vasomotion, a rhythmic dilation and constriction of the arterioles that is involved in fluid and nutrient exchange and modulation of local vascular resistance. In a separate set of experiments, blood flow in the contralateral internal spermatic artery was measured with an ultrasonic flow probe during acute torsion.
  
  
  RESULTS
  Following 720 degrees torsion, the amplitude of vasomotion in the contralateral testis increased 121% (29.0 +/- 3.9% versus 13.0 +/- 1.7%) compared with controls. Blood flow in the contralateral internal spermatic artery decreased 43% after 2 hours' torsion.
  
  
  CONCLUSIONS
  Acute spermatic cord torsion altered the microcirculation by increasing the amplitude of vasomotion and decreased total blood flow to the opposite testis. Because the hydraulic resistance of a blood vessel exhibiting vasomotion is always less than a vessel with the same average but static diameter, the observed microcirculatory changes may be an adaptive response to preserve local flow in the presence of decreased total flow. The long-term consequences of these changes in the microcirculation may affect testicular function and ultimately fertility.
mesh_terms: D000208:Acute Disease; D000818:Animals; D001158:Arteries / Q000502:physiology; D001160:Arterioles / Q000502:physiology; D008297:Male; D018715:Microscopy, Video; D051381:Rats; D017208:Rats, Wistar; D012039:Regional Blood Flow / Q000502:physiology; D013086:Spermatic Cord Torsion / Q000503:physiopathology*; D013737:Testis / Q000098:blood supply*; D014661:Vasoconstriction / Q000502:physiology; D014664:Vasodilation / Q000502:physiology