TY - JOUR
T1 - Long-term effect of low energy laser irradiation on infarction and reperfusion injury in the rat heart
AU - Yaakobi, Tali
AU - Shoshany, Yariv
AU - Levkovitz, Sara
AU - Rubin, Ofer
AU - Ben Haim, Shlomo A.
AU - Oron, Uri
PY - 2001/6
Y1 - 2001/6
N2 - Low-energy laser irradiation (LELI) has been found to modulate biological processes. The present study investigated the effect of LELI on infarct size after chronic myocardial infarction (MI) and ischemia-reperfusion injury in rats. The left anterior descending (LAD) coronary artery was ligated in 83 rats to create MI or ischemia-reperfusion injury. The hearts of the laser-irradiated (LI) rats received irradiation after LAD coronary artery occlusion and 3 days post-MI. At 14, 21, and 45 days post-LAD coronary artery permanent occlusion, infarct sizes (percentage of left ventricular volume) in the non-laser-irradiated (NLI) rats were 52 ± 12 (SD), 47 ± 11, and 34 ± 7%, respectively, whereas in the LI rats they were significantly lower, being 20 ± 8, 15 ± 6, and 10 ± 4%, respectively. Left ventricular dilatation (LVD) in the chronic infarcted rats was significantly reduced (50-60%) in LI compared with NLI rats. LVD in the ischemia-reperfusion-injured LI rats was significantly reduced to a value that did not differ from intact normal noninfarcted rats. Laser irradiation caused a significant 2.2-fold elevation in the content of inducible heat shock proteins (specifically HSP70i) and 3.1-fold elevation in newly formed blood vessels in the heart compared with NLI rats. It is concluded that LELI caused a profound reduction in infarct size and LVD in the rat heart after chronic MI and caused complete reduction of LVD in ischemic-reperfused heart. This phenomenon may be partially explained by the cardioprotective effect of the HSP70i and enhanced angiogenesis in the myocardium after laser irradiation.
AB - Low-energy laser irradiation (LELI) has been found to modulate biological processes. The present study investigated the effect of LELI on infarct size after chronic myocardial infarction (MI) and ischemia-reperfusion injury in rats. The left anterior descending (LAD) coronary artery was ligated in 83 rats to create MI or ischemia-reperfusion injury. The hearts of the laser-irradiated (LI) rats received irradiation after LAD coronary artery occlusion and 3 days post-MI. At 14, 21, and 45 days post-LAD coronary artery permanent occlusion, infarct sizes (percentage of left ventricular volume) in the non-laser-irradiated (NLI) rats were 52 ± 12 (SD), 47 ± 11, and 34 ± 7%, respectively, whereas in the LI rats they were significantly lower, being 20 ± 8, 15 ± 6, and 10 ± 4%, respectively. Left ventricular dilatation (LVD) in the chronic infarcted rats was significantly reduced (50-60%) in LI compared with NLI rats. LVD in the ischemia-reperfusion-injured LI rats was significantly reduced to a value that did not differ from intact normal noninfarcted rats. Laser irradiation caused a significant 2.2-fold elevation in the content of inducible heat shock proteins (specifically HSP70i) and 3.1-fold elevation in newly formed blood vessels in the heart compared with NLI rats. It is concluded that LELI caused a profound reduction in infarct size and LVD in the rat heart after chronic MI and caused complete reduction of LVD in ischemic-reperfused heart. This phenomenon may be partially explained by the cardioprotective effect of the HSP70i and enhanced angiogenesis in the myocardium after laser irradiation.
KW - Angiogenesis
KW - Heat shock proteins
KW - Ischemia
KW - Laser
KW - Myocardial infarction
UR - http://www.scopus.com/inward/record.url?scp=0034996437&partnerID=8YFLogxK
U2 - 10.1152/jappl.2001.90.6.2411
DO - 10.1152/jappl.2001.90.6.2411
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AN - SCOPUS:0034996437
SN - 8750-7587
VL - 90
SP - 2411
EP - 2419
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
IS - 6
ER -