Pain makes the heart grow stronger
Scientists working with both mice and people have found that painkillers could actually hinder the body’s recovery after a heart attack. The surprising results challenge the current practice of providing strong painkillers to people who have just suffered a heart attack and also hint at new ways of repairing damaged hearts.
Collectively, heart and circulatory diseases cause more than one in three of all deaths in the UK, accounting for more than 191,000 deaths each year. A heart attack occurs when the heart is starved of oxygen due to arteries becoming blocked.
The researchers found that a molecule involved in the sensation of pain is released from nerves in the heart during an attack. The signalling molecule, called Substance P, instructs stem cells in the bone marrow to enter the bloodstream and travel to the area that has been starved of oxygen. These stem cells then form new blood vessels to bypass the blockage and provide extra blood to the damaged heart muscle, aiding recovery.
The discovery is significant because morphine and other strong painkillers work by blocking the release of pain-inducing substances, including Substance P. This explains why previous studies have found higher mortality rates in patients given morphine shortly after suffering a heart attack. The team uncovered the role of Substance P in mice but preliminary experiments suggest it has the same role in people too.
The findings also raise the possibility of harnessing Substance P to mobilise the body’s own repair system to fix damaged heart tissue.