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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2002-4-10
pubmed:abstractText
To determine whether lung capillary pressure regulates surfactant secretion, we viewed alveoli of the constantly inflated, isolated blood-perfused rat lung by fluorescence microscopy. By alveolar micropuncture we infused fura 2 and lamellar body (LB)-localizing dyes for fluorescence detection of, respectively, the alveolar cytosolic Ca(2+) concentration ([Ca(2+)](i)) and type II cell exocytosis. Increasing left atrial pressure (Pla) from 5 to 10 cmH(2)O increased septal capillary diameter by 26% and induced marked alveolar [Ca(2+)](i) oscillations that abated on relief of pressure elevation. The rate of loss of LB fluorescence that reflects the LB exocytosis rate increased fourfold after the pressure elevation and continued at the same rate even after pressure and [Ca(2+)](i) oscillations had returned to baseline. In alveoli pretreated with either 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-AM, the intracellular Ca(2+) chelator, or heptanol, the gap junctional blocker, the pressure-induced exocytosis was completely inhibited. We conclude that capillary pressure and surfactant secretion are mechanically coupled. The secretion initiates in a Ca(2+)-dependent manner but is sustained by Ca(2+)-independent mechanisms.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
1040-0605
pubmed:author
pubmed:issnType
Print
pubmed:volume
282
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
L912-6
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:11943654-Animals, pubmed-meshheading:11943654-Calcium, pubmed-meshheading:11943654-Capillaries, pubmed-meshheading:11943654-Cell Communication, pubmed-meshheading:11943654-Chelating Agents, pubmed-meshheading:11943654-Egtazic Acid, pubmed-meshheading:11943654-Exocytosis, pubmed-meshheading:11943654-Fluorescent Dyes, pubmed-meshheading:11943654-Gap Junctions, pubmed-meshheading:11943654-Heptanol, pubmed-meshheading:11943654-Hypertension, Pulmonary, pubmed-meshheading:11943654-Male, pubmed-meshheading:11943654-Microscopy, Fluorescence, pubmed-meshheading:11943654-Pulmonary Alveoli, pubmed-meshheading:11943654-Pulmonary Circulation, pubmed-meshheading:11943654-Pulmonary Surfactants, pubmed-meshheading:11943654-Rats, pubmed-meshheading:11943654-Rats, Sprague-Dawley, pubmed-meshheading:11943654-Stress, Mechanical
pubmed:year
2002
pubmed:articleTitle
Vascular regulation of type II cell exocytosis.
pubmed:affiliation
Department of Medicine, College of Physicians and Surgeons; and St. Luke's-Roosevelt Hospital Center, Columbia University, New York, New York 10019, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.