Working together with colleagues from the University of Jeruslam, Dr. Meliha Karsak found that mice with a particular gene defect have a lower bone density. This breakthrough is making "cannabinoidreceptors" a key focus of osteoporosis research.
"We know two types of cannabinoidreceptors, CB1 and CB2," explains Dr. Karsak. "The CB1 receptor is formed by nerve cells in the brain and is responsible for, among other things, the mental effect of cannabis. The CB2 receptor, on the other hand, does not occur in nerve cells; its function was previously unknown." To explore this function the scientists working with Bonn's senior brain expert Professor Dr. Andreas Zimmer have made genetic modifications in mice in order to switch off their CB2 receptor. Dr. Karsak summarises what happened: "The animals gradually lost their stabilising trabeculae. We found in these mice that the number of osteoclasts ?special cells that can break down the bone tissue –increases by almost 50 per cent."
Signal molecules regulate bone density
Together with a research group from Israel and England, Dr. Karsak was able to demonstrate that osteoclasts, as well as their opposite number, the osteoblasts, which are respo
Source:University of Bonn