This vivid tunnel is a slice through a rat's coronary artery – one of the vital blood vessels that feed the muscles of the heart – and it's in trouble. The white space in the middle, where blood would normally flow, is half the size it should be. And the red layer of muscle cells lining the tunnel is twice as thick as normal, while the blue layer around that (made up of a rubbery tissue called collagen) is also bigger than expected. What’s caused these problems is a cancer drug called doxorubicin, which was given to the animal over several weeks. Doxorubicin is used to treat some types of breast cancer and lymphoma but can also raise the risk of heart attacks. Scientists now know that the drug causes coronary arteries to narrow and thicken – a likely cause of these heart problems.
Written by Kat Arney
BPoD stands for Biomedical Picture of the Day. Managed by the MRC London Institute of Medical Sciences the website aims to engage everyone, young and old, in the wonders of biomedicine. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.