Upregulation of alveolar liquid clearance after fluid resuscitation for hemorrhagic shock in rats.
The primary objective of this study was to test the hypothesis that a catecholamine-dependent mechanism would upregulate alveolar liquid clearance after fluid resuscitation from 15 min of hemorrhagic shock. Anesthetized rats were hemorrhaged to a mean arterial pressure of 35 mmHg for 15 min and were resuscitated with a 4% albumin solution. Alveolar liquid clearance was measured 5 h later by the concentration of protein in the distal airspaces over 1 h after instillation of a 5% albumin solution into one lung. Hemorrhaged rats developed a severe metabolic acidosis that was associated with a significant rise-in plasma epinephrine levels throughout the study. There was a 60% increase in alveolar liquid clearance in hemorrhaged and resuscitated rats compared with control rats. Amiloride (10(-4) or 10(-6) M), propranolol (10(-4) M), or bilateral adrenalectomy inhibited the increase in alveolar liquid clearance. This effect was reproduced by the intravenous administration of epinephrine in adrenalectomized and hemorrhaged rats. Thus these data provide evidence for a catecholamine-dependent regulation of sodium transport that protects the airspaces against flooding several hours after fluid resuscitation from hemorrhagic shock.
Modelska
K
K
Department of Anesthesia, University of California, San Francisco 94143, USA.
Matthay
M A
MA
McElroy
M C
MC
Pittet
J F
JF
D000315:Adrenalectomy; D000584:Amiloride / Q000008:administration & dosage / Q000494:pharmacology; D000818:Animals; D004837:Epinephrine / Q000008:administration & dosage / Q000494:pharmacology; D005440:Fluid Therapy; D007262:Infusions, Intravenous; D008297:Male; D011433:Propranolol / Q000008:administration & dosage / Q000494:pharmacology; D011650:Pulmonary Alveoli / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012151:Resuscitation; D012771:Shock, Hemorrhagic / Q000628:therapy*
D000584:Amiloride; D011433:Propranolol; D004837:Epinephrine