Cerebral Protein Turnover: Aspects and Problems
Our ideas and our knowledge about the mechanisms of cerebral protein synthesis and degradation, the metabolic rates of these processes, and the factors which alter these rates have undergone major changes in the past few decades. Because of the complexity of the task, brain has not been examined in this respect until comparatively recently. Due to the technical difficulties, such as the limited rates of access of labeled amino acids across the blood-brain barrier, it was thought that protein turnover is very slow or absent in the nervous system, a not unreasonable conclusion, considering that the brain lacks significant regenerative capacity and is the site of permanent information (memory). Now we know that protein metabolism is highly active in the brain and is involved in many crucial functions such as neuropeptide formation and enzyme activation. Both synthesis and degradation rates undergo numerous changes in development and aging, and they can be influenced by pathological and environmental factors. It is hoped that further knowledge of the mechanisms involved will open up a variety of therapeutic and diagnostic possibilities. With PET it may now be possible to study protein metabolism in the living human brain in vivo, a possibility only dreamed of till recently.
KeywordsProtein Metabolism Synthesis Rate Incorporation Rate Brain Protein Pulse Label
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