Incorporation of [14C] amino acids into the proteolipid of subcellular preparations of rat brain in vitro

IN a previous report (MOKRASCH and MANNER, 1963) some of the characteristics of the incorporation of p4C]amino acids and pT]palmitate into the proteolipid from rat brain slices were detailed. This report deals with a further resolution of the incorporating system in centrifugal subfractions of rat brain homogenate. Some similarities in the reaction condition requirements are seen when the incorporations for slices are compared with those for particle preparations. Differences between the incorporation of p4C]amino acids into ptoteolipid by the system used here and incorporation by microsomal systems ate several. A report with preliminary information on the particulate system has appeared (MOKRASCH, 1963).     

Incorporation of 14C from glucose into amino acids in brain in vitro in the presence of organo- and inorganic lead and pyridoxal phosphate

The incorporation of label from U14C glucose into glutamic acid, glutamine and GABA remained unaltered with the presence of lead acetate in the medium whereas tetraethyl lead (TEL) affected the incorporation in a characteristic manner in different regions of brain. Glucose uptake however was not influenced by TEL. Pyridoxal phosphate was found to reverse the effect of TEL on the incorporation especially in cerebellum and brainstem but with little effect in cerebral cortex. These findings suggest that the alterations in the GABA metabolism in TEL toxicity could be restored to some extent by pyridoxine in discrete brain areas.