Making arteriosclerosis visible

Arteriosclerosis, also known as hardening of the arteries, can lead to heart attacks or strokes and is the most common cause of death worldwide. There are several known factors that lead to deposits and thickening in the walls of the blood vessels, such as high cholesterol levels. These so-called plaques often severely constrict blood vessels or even lead to the formation of blood clots, so that the heart or brain are no longer adequately supplied and are damaged as a result of a lack of oxygen.

The new method for investigating such constrictions of the blood vessels, known as atherosclerosis, is based on an artificial positron emission tomography (PET) reporter enzyme. This is produced specifically in the vascular muscle cells of mice using a genetic trick. It causes a radioactive substance, the PET tracer, to accumulate in these cells. The radioactive radiation, which is harmless to the animal, is recognised by PET and visualised on a screen. PET is a clinically established method that is used, for example, to examine tumour patients. As a non-invasive procedure, PET imaging places less strain on the body than many other examinations.

Recognising exactly where arteriosclerosis begins

By combining PET with magnetic resonance imaging (MRI), the research team is now able to track the position and number of vascular muscle cells in the body. With this method, we can observe in living animals how the labelled cells are involved in the development of atherosclerosis," explains first author and study leader Dr Susanne Feil from the Interfaculty Institute of Biochemistry (IFIB) at the University of Tübingen. For example, it is possible to see where vascularised muscle cells accumulate in blood vessels and contribute to calcification. By visualising such cell accumulations, conclusions can be drawn as to whether changes are harmless or could have life-threatening effects, for example because they could lead to vascular occlusions and infarctions.

Less animal testing necessary

In addition, significantly fewer laboratory animals are required compared to previous methods, according to the research team. The labelled cells could be tracked non-invasively over many weeks in the same animal and thus also the development of atherosclerosis. In addition, long-term studies can be used to obtain significantly more data per animal, and of better quality, as there are no inter-individual fluctuations in the measured values.

Article from "medizin & technik" from 04/04/2023