Longitudinal evaluation of local muscle conditions in a rat model of gastrocnemius muscle injury using an in vivo imaging system.
This study aimed to evaluate the time course of local changes during the acute phase of gastrocnemius muscle strain, in a rat model, using an in vivo imaging system. Thirty-eight, 8-week-old Sprague-Dawley male rats were used in our study. Experimental injury of the right gastrocnemius muscle was achieved using the drop-mass method. After inducing muscle injury, a liposomally formulated indocyanine green derivative (LP-iDOPE, 7 mg/kg) was injected intraperitoneally. We evaluated the muscle injuries using in vivo imaging, histological examinations, and enzyme-linked immunosorbent assays. The fluorescence peaked approximately 18 h after the injury, and decreased thereafter. Histological examinations revealed that repair of the injured tissue occurred between 18 and 24 h after injury. Quantitative analyses for various cytokines demonstrated significant elevations of interleukin-6 and tumor necrosis factor-α at 3 and 18 h post-injury, respectively. The time course of fluorescence intensity, measured using in vivo imaging, demonstrated that the changes in cytokine levels and histopathologic characteristics were consistent. Specifically, these changes reached peaked 18 h post-injury, followed by trends toward recovery.
Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan.
Kazuhide
K
Inage
Department of Orthopaedic Surgery, National Hospital Organization Chiba Medical Center, Chiba, Japan.
Yoshihiro
Y
Sakuma
Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan.
Kazuyo
K
Yamauchi
Department of Bioinformatics, Graduate School of Medicine, Chiba University, Chiba, Japan.
Akiko
A
Suganami
Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan.
Sumihisa
S
Orita
Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan.
Go
G
Kubota
Department of Orthopaedic Surgery, Teikyo University Chiba Medical Center, Chiba, Japan.
Yasuhiro
Y
Oikawa
Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan.
Takeshi
T
Sainoh
Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan.
Jun
J
Sato
Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan.
Kazuki
K
Fujimoto
Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan.
Yasuhiro
Y
Shiga
Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan.
Kazuhisa
K
Takahashi
Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan.
Seiji
S
Ohtori
Department of Bioinformatics, Graduate School of Medicine, Chiba University, Chiba, Japan.
Yutaka
Y
Tamura
D000818:Animals; D004797:Enzyme-Linked Immunosorbent Assay; D005456:Fluorescent Dyes / Q000008:administration & dosage; D007208:Indocyanine Green / Q000008:administration & dosage; D008081:Liposomes; D008297:Male; D018482:Muscle, Skeletal / Q000293:injuries* / Q000473:pathology; D017207:Rats, Sprague-Dawley; D013180:Sprains and Strains / Q000473:pathology*
D005456:Fluorescent Dyes; D008081:Liposomes; D007208:Indocyanine Green
gastrocnemius muscle strain; in vivo imaging; local muscle condition; muscle injury; rat model of muscle injury