499 
INVITED DISCUSSION 
EFFECT OF 4-METHOXYMETHYLPYRIDOXINE 
AND CARBONYL-TRAPPING AGENTS ON AMINO ACID 
CONTENT OF MAMMALIAN BRAIN AND OTHER TISSUES 
CLAUDE F. BAXTER anp EUGENE ROBERTS 
Department of Biochemistry, Medical Research Institute, City of Hope Medical Center, 
Duarte, Calif. (U.S.A.) 
Evidence for the relative constancy of the levels of free or loosely bound amino 
acids in tissues of mature animals has been documented in a preceding paper at this 
Symposium!. Certain abnormal conditions, the administration of non-physiological 
doses of hormones and treatment with pharmacologically active agents, can elicit 
responses which may include a change in the level of one or more amino acids in 
specific tissues 77 vivo. These changes may be the result of metabolic changes affecting 
enzyme systems, permeability, transport mechanisms, etc. This paper is limited in 

Fig. 1-4. Effect of 4-methoxymethylpyridoxine upon the concentration of amino acids of brain 
cortex in rats*. Injected dose: 250 mg/kg body wt. This was administered in two doses, 2.5 h apart. 
Animals were decapitated 3.5 h after the first injection. All odd numbered chromatograms re 
present tissues from normal control animals; all even numbered chromatograms illustrate changes 
in the tissues of treated animals. 
* For footnote see page 500. 
References p. 508 
