Brain Protein Synthesis in Normal and Demented Patients. A Study by P.E.T. with exp 11 C-L Methionine

摘要

A compartmental model representing protein synthesis in the brain was validated experimentally in 9 baboons. After sequential injections of exp 11 C, exp 3 H and exp 14 C methionines on the same animal, followed by P.E.T. recording of the gamma activity in a chosen brain section with time, the distribution of methionine injected into the different compartments of the model after a bolus was measured by crushing and precipitation with T.C.A. The agreement between direct in vitro findings and computed results is excellent. This method of studying brain protein synthesis in vivo was applied to 28 Alzheimer dementia cases and 20 normal subjects of the same age. The correlation between the results of clinical and psychometric tests and the brain protein synthesis activity confirms an anomaly in this biochemical synthesis process during the illness. A 65% fall in activity may be found in the frontal lobes of certain patients. (Atomindex citation 14:742338)