The effect of hyperventilation on distal nephron hydrogen ion secretion.
AUTOR(ES)
Giammarco, R A
RESUMO
This study was designed to determine the effect of acute hyperventilation on distal nephron hydrogen ion secretion. The blood PCO2 declined and stabilized rapidly when bicarbonate loaded rats were hyperventilated. In contrast, the urine PCO2 declined slowly, resulting in an early increase in the urine minus blood (U-B) PCO2 which could not be obliterated by carbonic anhydrase infusion. Within approximately 50 min, the U-B PCO2 in the hyperventilated and carbonic anhydrase infused rats approached zero. Consequently, equilibrium between collecting duct urine and arterial blood PCO2 was then presumed to exist. This provided the basis for the subsequent studies on a series of rats. The U-B PCO2 decreased from a control of 22+/-1 mm Hg (mean+/-SEM) to 11+/-2 mm Hg (mean+/-SEM) with hypocapnia, and rose again to its control value when the blood PCO2 returned to prehyperventilation values. This decline in U-B PCO2 with acute hyperventilation could not be attributed to changes in urine flow, phosphate, or bicarbonate excretion, suggesting, therefore, a decrease in distal nephron (probably collecting duct) hydrogen ion secretion with acute hyperventilation. Possible pitfalls in the interpretation of the UB PCO2 are illustrated.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=333157Documentos Relacionados
- Actions of hydrogen sulphide on ion transport across rat distal colon
- The effect of altered sodium concentration in the distal nephron segments on renin release
- EFFECT OF HYDROGEN-ION CONCENTRATION ON CHLORELLA PHOTOSYNTHESIS
- Relationship of urinary and blood carbon dioxide tension during hypercapnia in the rat. Its significance in the evaluation of collecting duct hydrogen ion secretion.
- THE EFFECT OF CHANGES IN HYDROGEN ION CONCENTRATION ON THE PULMONARY CIRCULATION*