Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020440 (hypercapnia)
 7,939 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Movement of chloride from blood to cerebrospinal fluid (CSF) is one of the factors that may be involved in regulation of CSF [Cl-], which is important to CSF acid-base balance. We made quantitative measurements of the unidirectional flux of radiolabeled chloride between blood and CSF in anesthetized dogs, using 38Cl, a short-lived isotope (half-life 37.3 min). This allowed multiple studies to be performed in a given animal. A three-compartment model for the blood, CSF, brain extracellular fluid, and ventriculocisternal perfusion system was used to determine the flux rate. With normocapnia, the flux was 0.01.1 min-1. The influx could be reproducibly measured for three separate determinations in the same animal over a period of 6 h, being 98 +/- 6% of the control first run on the second run and 113 +/- 6% on the third. Furosemide and bumetanide, inhibitors of sodium-coupled chloride movement, lowered the flux to 43 +/- 3% and 55 +/- 6% of control, respectively. The combination of hypercapnia and furosemide lowered the influx to 63 +/- 9% of control. These results indicate that a major mechanism of chloride entry into CSF is sodium-coupled chloride transport.
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PMID:Chloride flux from blood to CSF: inhibition by furosemide and bumetanide. 369 96

Furosemide is known to influence the activity of vagally mediated mechanoreceptors in the airways. Because vagal afferent fibers may play an important role in modulation of the sensation of dyspnea, it is possible that inhaled furosemide may modify the sensation of dyspnea. In a double-blind, randomized, crossover study, we compared the effect of inhaled furosemide on dyspneic sensation with that of placebo. Severe dyspneic sensation was induced in 12 healthy subjects in two ways: (1) breathholding and (2) loaded breathing with a combination of inspiratory resistive load (240 cm H(2)O/L/s) and hypercapnia induced by extra mechanical dead space (0.26 L). Subjects were asked to rate their sensation of respiratory discomfort using a visual analogue scale (dyspneic VAS). Breathholding times and changes in dyspneic VAS score during a 5-min period of loaded breathing were measured after inhalation of placebo and furosemide (40 mg). Total breathholding time after inhalation of furosemide (median, 93 [interquartile range, 78 to 112]s) was prolonged compared with the total breathholding time after placebo inhalation (67 [47-74]s). We also found that respiratory discomfort during loaded breathing after inhalation of furosemide develops more slowly and is less than that observed after inhalation of placebo. Our findings indicate that inhaled furosemide greatly alleviates the sensation of dyspnea induced experimentally by breathholding and by a combination of resistive loading and hypercapnia.
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PMID:Inhaled furosemide greatly alleviates the sensation of experimentally induced dyspnea. 1085 74

Recent evidence suggests that inhaled furosemide relieves dyspnoea in patients and in normal subjects made dyspnoeic by external resistive loads combined with added dead-space. Furosemide sensitizes lung inflation receptors in rats, and lung inflation reduces air hunger in humans. We therefore hypothesised that inhaled furosemide acts on the air hunger component of dyspnoea. Ten subjects inhaled aerosolized furosemide (40 mg) or placebo in randomised, double blind, crossover experiments. Air hunger was induced by hypercapnia (50+/-2 mmHg) during constrained ventilation (8+/-0.9 L/min) before and after treatment, and rated by subjects using a 100 mm visual analogue scale. Subjects described a sensation of air hunger with little or no work/effort of breathing. Hypercapnia generated less air hunger in the first trial at 23+/-3 min after start of furosemide treatment (58+/-11% to 39+/-14% full scale); the effect varied substantially among subjects. The mean treatment effect, accounting for placebo, was 13% of full scale (P=0.052). We conclude that 40 mg of inhaled furosemide partially relieves air hunger within 1h and is accompanied by substantial diuresis.
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PMID:Effect of inhaled furosemide on air hunger induced in healthy humans. 1693 35