title: Laceration in rat gastrocnemius. Following-up muscle repairing by ultrasound biomicroscopy (in vivo), contractility test (ex vivo) and histopathology.
abstract: OBJECTIVE
  Implement a laceration protocol of the rat lateral gastrocnemius (LG) and following-up its repair with ultrasound biomicroscopy (UBM), contractility tests and histology.
  
  
  METHODS
  Sixty-three male Wistar rats were distributed into two groups. One, with sub-groups GI, GII and GIII (n=12), each containing right LG lacerated (n=6), control and sham (n=3) animals. LG muscles in GI, GII and GIII were inspected by UBM (40 MHz) immediately after, 14 and 28 days post-surgery and thereafter excised with four (GI), 14 (GII) and 28 (GIII) days post-surgery for histology. Animals in second group were distributed into right LG lacerated and control sub-groups. LG muscles in lacerated sub-group were submitted to contractility tests at four (n=8), 14 (n=8) and 28 (n=8) days post-surgery, while in the control sub-group (n=5) were submitted to contractility tests along the course of the experiments.
  
  
  RESULTS
  Descriptive findings agreed between the lesion model, muscle repair, UBM images and histology. Contractility results for right LG were different (p<0.05) between control and injured muscle with four and 14 days post-surgery, at tetanic stimulating frequencies (50 and 70 Hz).
  
  
  CONCLUSIONS
  A laceration protocol of the lateral gastrocnemius was implemented and ultrasound biomicroscopy, contractility and histology findings agreed regarding the following-up of injured muscle repair.
authors: Department of Surgery, School of Medicine, Federal University of Rio de Janeiro, Brazil.
authors: Carlos Martins
authors: CM
authors: Ferreira Filho
authors: Department of Basic and Clinical Pharmacology, Biomedical Science Institute, UFRJ, Rio de Janeiro, RJ, Brazil.
authors: Ananssa Maíra dos Santos
authors: AM
authors: Silva
authors: Department of Basic and Clinical Pharmacology, Biomedical Science Institute, UFRJ, Rio de Janeiro, RJ, Brazil.
authors: Roberto Takashi
authors: RT
authors: Sudo
authors: Carlos Chagas Filho Institute, UFRJ, Rio de Janeiro, RJ, Brazil.
authors: Christina Maeda
authors: CM
authors: Takiya
authors: Department of Surgery, School of Medicine, UFRJ, Rio de Janeiro, RJ, Brazil.
authors: João Carlos
authors: JC
authors: Machado
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D022125:Lacerations / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D008297:Male; D033401:Microscopy, Acoustic / Q000379:methods; D032342:Muscle Cells / Q000502:physiology; D009119:Muscle Contraction / Q000502:physiology; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging / Q000293:injuries* / Q000503:physiopathology; D017208:Rats, Wistar; D012038:Regeneration / Q000502:physiology*; D015203:Reproducibility of Results; D013997:Time Factors