Low level laser treatment of bone marrow helps heal hearts after a heart attack

A fascinating paper published in the journal Lasers in Surgery and Medicine shows that low-level laser treatment of bone marrow can have profound effects on the ability of bone marrow stem cells to repair a heart after a heart attack.

The paper’s authors are H Tuby, L Maltz, and Uri Oron, who are members of the Zoology department at Tel-Aviv University, Tel-Aviv, Israel. The title of the paper is “Induction of autologous mesenchymal stem cells in the bone marrow by low-level laser therapy has profound beneficial effects on the infarcted rat heart,” and it was published in the July edition of Lasers in Surgery and Medicine, 2001;43(5):401-109.

Oron and his co-workers have been studying the effects of photobiostimulation with low-level lasers on injured tissues. Their recent work established that application of low energy laser irradiation (LELI) to the site of injury in muscles, bone marrow or heart is beneficial. This irradiation does not heat the tissue and has not been found to cause adverse side effects.

The strategy of this study is rather simple: LELI on bone marrow stem cells after an laboratory animal has suffered a heart attack. The stimulated bone marrow stem cells might migrate to the injured heart and repair it. They used Sprague-Dawley rats, and induced heart attacks in those rats. Then they subjected the bone marrow of those rats to LELI 20 minutes or four hours after the heart attack. They also had rats that had not experienced heart attacks but were operated on as controls, and rats that had suffered heart attacks but were not treated with LELI. For those interested, they used a Ga-Al-As diode laser, power density 10 mW/cm², for 100 seconds.

The results were astounding. The size of the infarction was reduced by 75% and dilation of the ventricle was reduced 75% in those animals treated with LELI 20 minutes after the heart attack. There was also a 25-fold increase in the density of bone marrow-derived cells in the heart relative to the non-LELI-treated controls. This indicates that LELI offers a new approach to induce bone marrow stem cells to move into the blood stream, arrive at the damaged heart and repair it. This mobilization of bone marrow stem cells great shrinks the scar caused by a heart attack in laboratory animals. Maybe it’s time for trials in larger animals and then a phase I clinical trial in humans?