Effect of hypercapnia and hypocapnia on tryptophan and tyrosine hydroxylation in rat brain.

The effects of induced hypo- and hypercapnia upon the rate of hydroxylation of tryptophan and tyrosine in the rat brain were studied by measuring the accumulation of 5-HTP and DOPA following administration of the aromatic L-aminoacid decarboxylase inhibitor 3-hydroxybenzylhydrazine HCl (NSD 1015). The results suggest that the hydroxylation of tryptophan varies directly with the tissue Po2. On the other hand, the hydroxylation of tyrosine did not show a simple relationship to Po2 but appeared to be influenced by pH changes.

[1]  J. Davis,et al.  Effect of hypoxia on tyrosine and tryptophan hydroxylation in unanaesthetized rat brain , 1973, Journal of neurochemistry.

[2]  B. Siesjö,et al.  THE EFFECT OF HYPERCAPNIC ACIDOSIS UPON SOME GLYCOLYTIC AND KREBS CYCLE‐ASSOCIATED INTERMEDIATES IN THE RAT BRAIN , 1972, Journal of neurochemistry.

[3]  B. Siesjö,et al.  Cerebral metabolism in hypoxic hypoxia. I. Pattern of activation of glycolysis: a re-evaluation , 1975, Brain Research.

[4]  J. Davis,et al.  THE EFFECT OF HYPOXIA ON MONOAMINE SYNTHESIS, LEVELS AND METABOLISM IN RAT BRAIN , 1973, Journal of neurochemistry.

[5]  H. Green,et al.  Demonstration, characterization, and assay procedure of tryptophan hydroxylase in rat brain. , 1966, Analytical biochemistry.

[6]  A. Carlsson,et al.  Brain Tryptophan Hydroxylation: Dependence on Arterial Oxygen Tension , 1973, Science.

[7]  B. Siesjö,et al.  THE INFLUENCE OF HYPOCAPNIA UPON INTRACELLULAR pH AND UPON SOME CARBOHYDRATE SUBSTRATES, AMINO ACIDS AND ORGANIC PHOSPHATES IN THE BRAIN , 1973, Journal of neurochemistry.

[8]  S. Kaufman,et al.  THE INHIBITION OF PHENYLALANINE AND TYROSINE HYDROXYLASES BY HIGH OXYGEN LEVELS , 1972, Journal of neurochemistry.

[9]  B. Siesjö,et al.  THE EFFECT OF MODERATE AND MARKED HYPERCAPNIA UPON THE ENERGY STATE AND UPON THE CYTOPLASMIC NADH/NAD+ RATIO OF THE RAT BRAIN , 1972, Journal of neurochemistry.

[10]  N. Lassen,et al.  Blood flow and metabolic rate for oxygen in the cerebral cortex of the rat. , 1973, Acta physiologica Scandinavica.

[11]  J. Folbergrovaa,et al.  PATTERNS OF CHANGES IN BRAIN CARBOHYDRATE METABOLITES, AMINO ACIDS AND ORGANIC PHOSPHATES AT INCREASED CARBON DIOXIDE TENSIONS , 1974 .

[12]  G. M. Walton,et al.  Adenosine triphosphate conservation in metabolic regulation. Rat liver citrate cleavage enzyme. , 1967, The Journal of biological chemistry.

[13]  B. Siesjö,et al.  THE EFFECT OF HYPERCAPNIA UPON INTRACELLULAR pH IN THE BRAIN, EVALUATED BY THE BICARBONATE‐ CARBONIC ACID METHOD AND FROM THE CREATINE PHOSPHOKINASE EQUILIBRIUM , 1972, Journal of neurochemistry.

[14]  B. Siesjö,et al.  Brain energy metabolism in hypoxemia. , 1972, Scandinavian journal of clinical and laboratory investigation.

[15]  O. Siggaard‐Andersen.  TITRATABLE ACID OR BASE OF BODY FLUIDS , 1966, Annals of the New York Academy of Sciences.

[16]  B. Siesjö,et al.  The influence of arterial hypoxemia upon labile phosphates and upon extracellular and intracellular lactate and pyruvate concentrations in the rat brain. , 1971, Scandinavian journal of clinical and laboratory investigation.