Regional ionic and albumin content of fluid in the tracheobronchial tree in dogs.
We have devised a technique for collecting airway fluid from the bronchi in order to investigate the biochemical indices of airway fluid in normal dogs and the changes produced in them by pharmacological interventions. We collected airway fluid from the trachea by a screen technique and by means of filter paper cylinders inserted through a fiberoptic bronchoscope (the new method) and from main and segmental bronchi by the new method only. When bronchial fluid was compared with plasma, the concn of albumin was found to be much lower, Na+ lower, and Cl- either higher or similar. The Na+:Cl- ratio was lowest in fluid from the trachea (1.04) and highest in fluid from segmental bronchi (1.14), but was significantly lower at all levels than in plasma (1.32). Subcutaneous administration of methacholine chloride significantly increased the weight of airway fluid collections. Infusion of 5% hypertonic saline induced changes in the concns of electrolytes (but not of albumin) that correlated with changes in the plasma. The major differences in electrolyte and albumin concns in airway fluid and plasma likely reflect a bidirectional transepithelial flux of these ions. The regional differences in electrolyte concns and ratios may be due to differences in anatomic structure and in the functioning of ionic pumps along the tracheobronchial tree.
D000418:Albumins / Q000032:analysis*; D000818:Animals; D001826:Body Fluids / Q000032:analysis*; D001980:Bronchi / Q000378:metabolism*; D002712:Chlorides / Q000032:analysis; D004285:Dogs; D007477:Ions / Q000032:analysis*; D016210:Methacholine Chloride; D008688:Methacholine Compounds / Q000494:pharmacology; D010949:Plasma / Q000032:analysis; D011188:Potassium / Q000032:analysis; D012462:Saline Solution, Hypertonic / Q000494:pharmacology; D012964:Sodium / Q000032:analysis; D014132:Trachea / Q000378:metabolism*
D000418:Albumins; D002712:Chlorides; D007477:Ions; D008688:Methacholine Compounds; D012462:Saline Solution, Hypertonic; D016210:Methacholine Chloride; D012964:Sodium; D011188:Potassium