Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0085383 (hypocapnia)
 1,697 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The influence of hypoxemia on the brain content of several organic acids and NH+4, AND ITS RELATIONship to the accompanying hypocapnia was studied in unanesthetized rats subjected to hypoxemia for periods ranging between 2 hours and 7 days. Under acute conditions, 'mild' hypoxemia (FO2 = 6--7%), these increases were greater and accompanied by increased gamma-aminobutyric acid (GABA) and decreased glutamic and aspartic acid levels; glutamine and NH+4 remained normal. When hypocapnia was prevented, 'severe' hypoxemia induced only a rise in GABA and slight elevations in lactic and alpha-ketoglutaric acid. During prolonged severe hypoxemia, the effects on the brain amino acids were maintained throughout, indicating that they are independent from the intracerebral pH which should progressively normalize. The effect on lactic acid gradually disappeared. The results show that during hypocapnic hypoxemia the rise in brain GABA is hypoxemia dependent, the decrease in glutamic and aspartic acid is hypocapnia dependent and the increase in lactic acid is in a large way alkalosis dependent.
 ...
PMID:Brain amino acids in conscious rats in chronic normocapnic and hypocapnic hypoxemia. 92

Acute respiratory alkalosis (blood pH, 7.60; arterial PCO2, 15 mmHg (1 mmHg = 133.322 Pa); plasma bicarbonate, 14 mM) was induced in nine anesthetized dogs by increasing their respiratory rate and depth. Renal glutamine extraction and ammonia production expressed per 100 mL of glomerular filtration rate did not change during acute hypocapnia, whereas arterial glutamine concentration decreased significantly from 0.47 to 0.36 mM. Hypocapnia did not change plasma potassium concentration and its urinary excretion. Acute hypocapnia increased lactate extraction and pyruvate production, whereas citrate extraction and glutamate and alanine production did not change. Citraturia remained minimal. Renal cortical glutamine concentration fell from 0.64 to 0.38 mM during hypocapnia while alpha-ketoglutarate, glutamate, malate, oxaloacetate, and citrate did not change. Lactate concentration rose from 1.1 to 2.0 mM. Glutamine concentration in the liver and muscle decreased following acute hypocapnia. Our data are compatible with the hypothesis that an acute respiratory alkalosis might not result in any change in the hydrogen ion concentration and (or) gradient between the mitochondrial matrix and the cytosol. Consequently, renal glutamine extraction and ammonia production are not reduced, renal cortical concentrations of relevant metabolites in the ammoniagenic pathway are not changed, and renal handling of citrate remains unaffected.
 ...
PMID:Renal metabolism and ammoniagenesis during acute respiratory alkalosis in the dog. 649 24