Isoproterenol improves ability of lung to clear edema in rats exposed to hyperoxia.

Abstract

Exposure of adult rats to 100% O(2) results in lung injury and decreases active sodium transport and lung edema clearance. It has been reported that beta-adrenergic agonists increase lung edema clearance in normal rat lungs by upregulating alveolar epithelial Na(+)-K(+)-ATPase function. This study was designed to examine whether isoproterenol (Iso) affects lung edema clearance in rats exposed to 100% O(2) for 64 h. Active Na(+) transport and lung edema clearance decreased by approximately 44% in rats exposed to acute hyperoxia. Iso (10(-6) M) increased the ability of the lung to clear edema in room-air-breathing rats (from 0.50 +/- 0.02 to 0.99 +/- 0. 05 ml/h) and in rats exposed to 100% O(2) (from 0.28 +/- 0.03 to 0. 86 +/- 0.09 ml/h; P < 0.001). Disruption of intracellular microtubular transport of ion-transporting proteins by colchicine (0. 25 mg/100 g body wt) inhibited the stimulatory effects of Iso in hyperoxia-injured rat lungs, whereas the isomer beta-lumicolchicine, which does not affect microtubular transport, did not inhibit active Na(+) transport stimulated by Iso. Accordingly, Iso restored the lung's ability to clear edema after hyperoxic lung injury, probably by stimulation of the recruitment of ion-transporting proteins (Na(+)-K(+)-ATPase) from intracellular pools to the plasma membrane in rat alveolar epithelium.

• Authors: F J Saldías, A Comellas, K M Ridge, E Lecuona, J I Sznajder
• Journal: Journal of applied physiology (Bethesda, Md. : 1985) (J Appl Physiol (1985)) Vol. 87 Issue 1 Pg. 30-5 (Jul 1999) ISSN: 8750-7587 [Print] United States
• PMID: 10409555 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Adrenergic beta-Agonists
• Carrier Proteins
• Sodium-Potassium-Exchanging ATPase
• Isoproterenol

Topics

• Adrenergic beta-Agonists (pharmacology)
• Animals
• Biological Transport, Active (drug effects)
• Carrier Proteins (metabolism)
• Cell Membrane (metabolism)
• Hyperoxia (complications, metabolism)
• Isoproterenol (pharmacology)
• Lung (drug effects, metabolism)
• Lung Injury
• Male
• Pulmonary Alveoli (drug effects, metabolism)
• Pulmonary Edema (drug therapy, etiology, metabolism)
• Rats
• Rats, Sprague-Dawley
• Sodium-Potassium-Exchanging ATPase (metabolism)