Cardiomyocyte transplantation does not reverse cardiac remodeling in rats with chronic myocardial infarction.
BACKGROUND
Several reports have documented the potential benefits of cell transplantation as an alternative to cardiac transplantation. This study was designed to investigate whether cardiomyocyte transplantation is effective in rats with chronic myocardial infarction.


METHODS
Syngeneic Lewis rats were used in this study. Chronic myocardial infarction was induced in rats by ligating the left anterior descending artery. Four weeks later, after left ventricular (LV) dysfunction with akinetic regions was confirmed by echocardiography, the rats were randomized into two groups: a group that received fetal cardiomyocyte transplantation (TX group; n = 11); and a group that received an intramyocardial injection of culture medium only (control group; n = 12).


RESULTS
Four weeks after treatment, the TX group had smaller end-systolic dimension (LVDs) (7.5 +/- 0.9 vs 8.9 +/- 0.8 mm, p < 0.01) and better fractional shortening (FS) (26.2 +/- 5.9 vs 17.7% +/- 5.1%, p < 0.01) than the control group. However, there were no differences in LV end-diastolic dimension, LVDs, and FS between baseline and post-treatment values in the TX group. In addition, plasma levels of atrial natriuretic peptide were not significantly different between the two groups 4 weeks after treatment. In microscopic examination, small amounts of transplanted cardiomyocytes were found only in the periinfarct area, not in the center of scar area, and a thicker ventricular wall in the infarct area was detected in the TX group.


CONCLUSIONS
Fetal cardiomyocyte transplantation prevented, but did not reverse, cardiac remodeling that was accompanied with heart failure in myocardial infarction rats. Further investigation is warranted for optimal clinical application to the failing heart.
Department of Cardiovascular Surgery, Kyoto University, Graduate School of Medicine, Japan.
Yutaka
Y
Sakakibara
Keiichi
K
Tambara
Fanglin
F
Lu
Takeshi
T
Nishina
Noritoshi
N
Nagaya
Kazunobu
K
Nishimura
Masashi
M
Komeda
D000818:Animals; D009320:Atrial Natriuretic Factor / Q000097:blood; D017690:Cell Transplantation; D002908:Chronic Disease; D004195:Disease Models, Animal; D005318:Fetal Heart / Q000166:cytology*; D008297:Male; D009203:Myocardial Infarction / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D009206:Myocardium / Q000166:cytology; D011897:Random Allocation; D051381:Rats; D011917:Rats, Inbred Lew; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology / Q000601:surgery
D009320:Atrial Natriuretic Factor