An article describing this research appears this week in the prestigious American journal PNAS (Proceedings of the National Academy of Sciences of the U.S.A.). The researchers, from the Bone Laboratory of the Hebrew University, are headed by Prof. Itai Bab, working in cooperation with Prof. Esther Shohami of the Laboratory for the Study of Bain Trauma; Prof. Raphael Mechoulam of the Hebrew University School of Pharmacy; doctoral students Orr Ofek, Vardits Krem and Yossi Tam; and master's degree student Meirav Fogel.
Substances made in the body called endocannabinoids are composed mainly of fatty acids which were discovered during the last 15 years. (The fatty acid anandamid was discovered by Prof. Mechoulam in 1992.) These materials, which are produced mainly in the brain, are present also in the bone and other tissues and have similar effects to those of the active components in hashish and marijuana, produced from the cannabis plant.
These substances bind to and activate two receptors, CB1 and CB2. The first is found in the nervous system and is responsible for the psychoactive effects of the active components in the cannabis plant and endocannanoids. The second receptor is found in the immune system. It is not known to be involved with psychoactive responses, and there has been little information about its physiological function.
The Hebrew University researchers discovered a high level of CB2 receptors in bone, and that this is required in order to preserve normal bone density. Together with their colleagues at the University of Bonn, Germany, Prof. Andreas Zimmer and Dr. Malia Karasek, they studied
Contact: Jerry Barach
The Hebrew University of Jerusalem