Free amino acids and related compounds in dog brain: post-mortem and anoxic changes, effects of ammonium chloride infusion, and levels during seizures induced by picrotoxin and by pentylenetetrazol.

TLDR: The cerebral levels of a large number of nitrogenous constituents have been determined in control experiments and during seizures induced by picrotoxin or by pentylenetetrazol in an attempt to classify different types of seizures on the basis of specific chemical patterns.

Abstract: PREVIOUS studies in this laboratory have been concerned with chemical changes in the brain associated with convulsive activity (STONE et al., 1960) as revealed by analysis of brain tissue after in vivo fixation with liquid air. The development by MOORE and STEIN (1954) of ion exchange procedures for the separation of amino acids has made it feasible to extend the study of cerebral constituents during convulsions to include many free amino acids and related substances. These compounds are of particular interest in view of recent investigations by GEIGER and his coworkers (1960 a, 6) indicating that protein turnover in the brain is accelerated during convulsive activity induced by pentylenetetrazol. Accordingly, the cerebral levels of a large number of nitrogenous constituents have been determined in control experiments and during seizures induced by picrotoxin or by pentylenetetrazol. In an attempt to classify different types of seizures on the basis of specific chemical patterns (STONE et al., 1960), the seizures induced by these two agents have been tentatively classed together as representing a type in which distinctive metabolic changes have not yet been observed. As an aid in the interpretation of any changes which might be observed during seizures or other conditions, it was considered essential to study also post-mortem changes and the effects of anoxia and of ammonium chloride infusion.