title: Beta-adrenergic modulation of lung fluid balance in acute P aeruginosa pneumonia in rats.
abstract: OBJECTIVE
  we investigated the effects of terbutaline, a ß(2)-adrenergic agonist, on lung permeability and alveolar fluid clearance (AFC) in acute lung injury (ALI).
  
  
  METHODS
  the study was conducted in vivo on a rat model of P aeruginosa (Pa)-induced ALI. Rats were randomly divided into five groups: the control group (saline group), Pa and saline group, Pa and terbutaline treated group receiving intratracheal instillation of terbutaline at 10(-4) M, Pa and terbutaline plus propranolol treated group (terbutaline+propranolol group) and Pa and propranolol treated group (propranolol group). Hemodynamics, airway pressures, arterial blood gases, extravascular lung water, lung permeability to protein evaluated by the extravascular accumulation of (125)I-albumin (EPE), bacterial counts, and alveolar fluid clearance (AFC) were measured.
  
  
  RESULTS
  4.5 hours after bacterial instillation, the lung wet-to-dry ratio and the EPE were significantly decreased in the terbutaline group compared to saline control group (respectively 4.31 ± 0.51 g/g versus 5.99 ± 0.5 g/g 4.18 ± 0.25 g/g and 148 ± 68 μL versus 349 ± 97 μL respectively p < 0.01). Treatment with terbutaline in the Pa-instilled group significantly increased basal AFC compared with the saline and Pa group, (respectively 22.3 ± 1.3% versus 12.5 ± 4.7%, p < 0.001). Intratracheal instillation of propranolol (10(-4) M) inhibited the effects of terbutaline on lung fluid balance.
  
  
  CONCLUSIONS
  Exogenous instillation of beta2-adrenergic have a beneficial effect on lung fluid balance following Pa pneumonia in rats, by reducing pulmonary endothelial permeability and increasing alveolar fluid clearance. These data suggest that exogenous beta-adrenergic therapy can protect against alveolar edema formation in acute P aeruginosa pneumonia.
authors: Service de Réanimation Polyvalente, Lille, France. laurent.robriquet@chru-lille.fr
authors: Laurent
authors: L
authors: Robriquet
authors: Eric
authors: E
authors: Kipnis
authors: Eric
authors: E
authors: Kipris
authors: Benoit
authors: B
authors: Guery
mesh_terms: D000208:Acute Disease; D055371:Acute Lung Injury; D058666:Adrenergic beta-2 Receptor Agonists / Q000494:pharmacology*; D000818:Animals; D002199:Capillary Permeability / Q000187:drug effects; D008168:Lung / Q000098:blood supply / Q000187:drug effects / Q000503:physiopathology; D008297:Male; D018410:Pneumonia, Bacterial / Q000188:drug therapy* / Q000503:physiopathology*; D011552:Pseudomonas Infections / Q000188:drug therapy* / Q000503:physiopathology*; D011654:Pulmonary Edema / Q000517:prevention & control; D051381:Rats; D017207:Rats, Sprague-Dawley; D013726:Terbutaline / Q000494:pharmacology*; D014882:Water-Electrolyte Balance / Q000187:drug effects*
chemical_list: D058666:Adrenergic beta-2 Receptor Agonists; D013726:Terbutaline