title: Compartmental and muscular response to closed soft tissue injury in rats investigated by oxygen-to-see and intravital fluorescence microscopy.
abstract: BACKGROUND
  Closed soft tissue injury (CSTI) induces local inflammation and progressive microvascular dysfunction. The aim of the study was to evaluate and compare the microvascular changes systematically in a precompartmental tissue injury by oxygen-to-see (O2C), a combined laser Doppler flowmetry and spectrophotometry system, and intravital fluorescence microscopy (IVM).
  
  
  METHODS
  Fourteen Wistar rats were subjected to a trauma and a control group (both n = 7). CSTI was performed on the left lower limb by means of a standardized impact device. Controls received a sham CSTI. Capillary blood flow (QRBC), oxygen saturation (sO2), and postcapillary filling pressure (rHb) were measured noninvasively by O2C assessed in 2-mm and 8-mm depth underneath the skin. Measurements were done before and after trauma and hourly up to 24 hours. IVM of the soleus muscle was performed after 24 hours.
  
  
  RESULTS
  Before CSTI, O2C parameters did not reveal a difference between both groups. Up to 2 hours after trauma, QRBC was significantly increased in 8-mm tissue depth. No significant changes of sO2 and rHb were noted compared with controls. In 2-mm depth, significantly reduced QRBC and rHb levels were observed compared with 8 mm but with no significant changes after CSTI. IVM showed a significant increase of postcapillary blood flow with decreased functional capillary density, increased macromolecular leakage, and increased nicotinamide adenine dinucleotide hydride.
  
  
  CONCLUSIONS
  After CSTI in rats, there was an immediate increase of compartmental capillary blood flow with a slight increase of muscle oxygen saturation and unchanged postcapillary venous filling pressures as sign of a redistribution of blood between soft and muscle tissue. The severity of pathologic changes in the compartment was not reflected by O2C but by IVM.
authors: Department of Trauma and Reconstructive Surgery, University of Rostock, Rostock, Germany. robertrotter@yahoo.de
authors: Robert
authors: R
authors: Rotter
authors: Robert
authors: R
authors: Kraemer
authors: Ioannis
authors: I
authors: Stratos
authors: Peter
authors: P
authors: Vogt
authors: Brigitte
authors: B
authors: Vollmar
authors: Thomas
authors: T
authors: Mittlmeier
authors: Karsten
authors: K
authors: Knobloch
mesh_terms: D000818:Animals; D002196:Capillaries / Q000293:injuries / Q000473:pathology / Q000503:physiopathology; D017078:Laser-Doppler Flowmetry; D008297:Male; D008833:Microcirculation; D008856:Microscopy, Fluorescence; D055806:Microvessels / Q000293:injuries / Q000473:pathology*; D018482:Muscle, Skeletal / Q000098:blood supply / Q000293:injuries* / Q000473:pathology / Q000503:physiopathology; D010100:Oxygen / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D017695:Soft Tissue Injuries / Q000473:pathology* / Q000503:physiopathology
chemical_list: D010100:Oxygen