title: Effect of postconditioning on dynamic expression of tenascin-C and left ventricular remodeling after myocardial ischemia and reperfusion.
abstract: BACKGROUND
  Tenascin-C (TNC), an extracellular matrix glycoprotein, is expressed transiently in distinct areas in association with active tissue remodeling. This study aimed to explore how ischemic postconditioning (PC) affects myocardial expression of TNC and ventricular remodeling using (125)I-labeled anti-TNC antibody ((125)I-TNC-Ab) in a rat model of ischemia and reperfusion.
  
  
  METHODS
  In control rats (n = 27), the left coronary artery (LCA) was occluded for 30 min followed by reperfusion for 1, 3, 7, and 14 days. PC (n = 27) was performed just after the reperfusion. At the time of the study, (125)I-TNC-Ab (1.0 to 2.5 MBq) was injected. Six to 9 h later, to verify the area at risk, (99m)Tc-MIBI (100 to 200 MBq) was injected intravenously just after the LCA reocclusion, with the rats sacrificed 1 min later. Dual tracer autoradiography was performed to assess (125)I-TNC-Ab uptake and area at risk. To examine the ventricular remodeling, echocardiography was performed 2 M after reperfusion in both groups.
  
  
  RESULTS
  In control rats, (125)I-TNC-Ab uptake ratio at 1 day after reperfusion was 3.73 ± 0.71 and increased at 3 days (4.65 ± 0.87), followed by a significant reduction at 7 days (2.91 ± 0.55, P < 0.005 vs 3 days) and14 days (2.01 ± 0.17, P < 0.005 vs 1 and 3 days). PC attenuated the (125)I-TNC-Ab uptake throughout the reperfusion time from 1 to 14 days; 2.59 ± 0.59 at 1 day, P < 0.05: 3.10 ± 0.42 at 3 days, P < 0.005: 1.93 ± 0.37 at 7 days, P < 0.05: 1.40 ± 0.07 at 14 days, P < 0.001. In echocardiography, PC reduced the ventricular end-diastolic and systolic dimensions (1.00 ± 0.06 cm to 0.83 ± 0.14 cm (P < 0.05) and 0.90 ± 0.15 cm to 0.62 ± 0.19 cm (P < 0.05), respectively) and prevented a decline of ventricular percentage fractional shortening (10.5 ± 3.7 to 28.2 ± 10.7, P < 0.005).
  
  
  CONCLUSIONS
  These data indicate that (125)I-TNC-Ab imaging may be a way to monitor myocardial injury, the subsequent repair process, and its response to novel therapeutic interventions like PC by visualizing TNC expression.
authors.affiliation: Department of Nuclear Medicine, Kanazawa University Hospital, 13-1 Takara-machi, Kanazawa, 920-8641 Japan.
authors.forename: Junichi
authors.initials: J
authors.lastname: Taki
authors.affiliation: Department of Nuclear Medicine, Kanazawa University Hospital, 13-1 Takara-machi, Kanazawa, 920-8641 Japan.
authors.forename: Anri
authors.initials: A
authors.lastname: Inaki
authors.affiliation: Department of Nuclear Medicine, Kanazawa University Hospital, 13-1 Takara-machi, Kanazawa, 920-8641 Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Wakabayashi
authors.affiliation: The Medical and Pharmacological Research Center Foundation, Wo 32, Inoyama, Hakui, 925-0613 Japan.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Matsunari
authors.affiliation: Department of Pathology and Matrix Biology, Mie University School of Medicine, 2-174 Edobashi, Tsu, 514-8507 Japan.
authors.forename: Kyoko
authors.initials: K
authors.lastname: Imanaka-Yoshida
authors.affiliation: Division of Pharmaceutical Sciences, Graduate School of Medical Sciences, Kanazawa University, Kakuma-machi, Kanazawa, 920-1192 Japan.
authors.forename: Kazuma
authors.initials: K
authors.lastname: Ogawa
authors.affiliation: Department of Nephrology and Cardiology, National Center for Global Health and Medicine, 1-21-1 Toyama, Shinjuku-ku, Tokyo, 162-8655 Japan.
authors.forename: Michiaki
authors.initials: M
authors.lastname: Hiroe
authors.affiliation: Division of Tracer Kinetics, Advanced Science Research Center, Kanazawa University, 13-1 Takara-machi, Kanazawa, 920-8640 Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Shiba
authors.affiliation: Department of Pathology and Matrix Biology, Mie University School of Medicine, 2-174 Edobashi, Tsu, 514-8507 Japan.
authors.forename: Toshimichi
authors.initials: T
authors.lastname: Yoshida
authors.affiliation: Department of Nuclear Medicine, Kanazawa University Hospital, 13-1 Takara-machi, Kanazawa, 920-8641 Japan.
authors.forename: Seigo
authors.initials: S
authors.lastname: Kinuya
keywords: I-125-anti-tenascin-C antibody; Myocardial ischemia and reperfusion; Postconditioning; Tenascin-C; Ventricular remodeling