title: Noninvasive detection of cardiac repair after acute myocardial infarction in rats by 111 In Fab fragment of monoclonal antibody specific for tenascin-C.
abstract: Left ventricular (LV) remodeling after acute myocardial infarction (MI) causes heart failure, and thus it is important to evaluate cardiac repair as the early stage of LV remodeling. Tenascin-C (TNC), an extracellular matrix glycoprotein, is transiently and abundantly expressed in the heart during the early stage of tissue remodeling after MI. However, it is not expressed in healthy adult heart. This study was undertaken to develop a new noninvasive diagnostic technique to detect cardiac repair after acute MI using 111 In Fab fragment of a monoclonal antibody specific for TNC. 111 In-anti-TNC-Fab was injected intravenously in 13 rats at 1 (D1, n = 3), 3 (D3, n = 5), and 5 (D5, n = 5) days after producing MI and in 5 sham-operated rats (S). We performed autoradiography and dual-isotope single-photon emission computed tomography imaging (SPECT) of 111 In-anti-TNC-Fab and 99mTc methoxyisobutyl isonitrile (MIBI). The radioactivity in the heart was significantly higher in D (D1, 0.45 +/- 0.06% injected-dose/g; D3, 0.64 +/- 0.12; D5, 0.38 +/- 0.07) than S (0.27 +/- 0.06, P < 0.01 versus D1 and D3, P < 0.05 versus D5). By autoradiography, higher radioactivities were observed in the infarcted area than in the noninfarcted area of MI hearts. Dual-isotope SPECT demonstrated the regional myocardial uptake of 111 In-anti-TNC-Fab, which was complementary to the perfusion image. The results of the present study indicated that we can localize the infarcted region in the heart by ex vivo and in vivo imaging methods using 111 In-anti-TNC-Fab, and suggested the potential usefulness of noninvasive detection of cardiac repair.
authors.affiliation: Department of Cardiovascular Science and Medicine, Chiba University Graduate School of Medicine, Chiba, Japan.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Odaka
authors.forename: Tomoya
authors.initials: T
authors.lastname: Uehara
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Arano
authors.forename: Sayaka
authors.initials: S
authors.lastname: Adachi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Tadokoro
authors.forename: Katsuya
authors.initials: K
authors.lastname: Yoshida
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hasegawa
authors.forename: Kyoko
authors.initials: K
authors.lastname: Imanaka-Yoshida
authors.forename: Toshimichi
authors.initials: T
authors.lastname: Yoshida
authors.forename: Michiaki
authors.initials: M
authors.lastname: Hiroe
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Irie
authors.forename: Shuji
authors.initials: S
authors.lastname: Tanada
authors.forename: Issei
authors.initials: I
authors.lastname: Komuro