Norlin A, Finley N, Abedinpour P, Folkesson HG. Alveolar liquid clearance in the anesthetized ventilated guinea pig.
THE AMERICAN JOURNAL OF PHYSIOLOGY 1998;
274:L235-43. [PMID:
9486208 DOI:
10.1152/ajplung.1998.274.2.l235]
[Citation(s) in RCA: 48] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Alveolar liquid clearance was examined in ventilated, anesthetized guinea pigs. An isosmolar 5% albumin solution was instilled into the lungs. Alveolar liquid clearance was studied over 1 h and was measured from the increase in alveolar protein concentration as water was reabsorbed. Basal alveolar liquid clearance was 38% of instilled volume. The high basal alveolar liquid clearance was not secondary to endogenous catecholamine release. Compared with control animals, epinephrine and the general beta-adrenergic agonist isoproterenol increased alveolar liquid clearance to approximately 50% of instilled volume (P < 0.05), whereas the beta 2-adrenergic agonist terbutaline was without effect. The stimulation of alveolar liquid clearance by epinephrine or isoproterenol was completely inhibited by the addition of the general beta-adrenergic inhibitor propranolol or the beta 1-adrenergic inhibitor atenolol. Alveolar liquid clearance was inhibited by the sodium-channel inhibitor amiloride by 30-40% in control animals and in animals treated with epinephrine or isoproterenol. Isoproterenol and epinephrine, but not terbutaline, increased adenosine 3',5'-cyclic monophosphate in in vitro incubated lung tissue. The results suggest that alveolar liquid clearance in guinea pigs is mediated partly through amiloride-sensitive sodium channels and that alveolar liquid clearance can be increased by stimulation of primarily beta 1-adrenergic receptors.
Collapse