RT Journal Article
SR Electronic
T1 Pulmonary hypertensive effects of lung inflation in chronic hypoxia: a study in rats
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP 277
OP 283
DO 10.1183/09031936.98.12020277
VO 12
IS 2
A1 GR Barer
A1 PC Russell
A1 K Kapeller, Jr
YR 1998
UL http://erj.ersjournals.com/content/12/2/277.abstract
AB Lung inflation was compared in isolated perfused lungs of control (C) and chronically hypoxic (CH) rats; in the latter, there is muscularization and loss of compliance in the pulmonary arterial system. During ventilation hypoxia, high alveolar pressure (Palv) elevated the pulmonary artery pressure (Ppa) less in C than in CH rats; Ppa fell during sustained inflation, rose on deflation, and after inflation hypoxic vasoconstriction was attenuated. Opposite changes took place in CH rats; Ppa often rose during inflation, fell on deflation, and after inflation hypoxic vasoconstriction was enhanced. Inflation also increased Ppa more in CH than C rats during air ventilation. Ppa/Palv relations measured during incremental inflation revealed normoxic tone in "extra-alveolar" vessels in both rat groups, which usually increased during hypoxia. In CH, but not C rats, there was also evidence for constriction in "alveolar" vessels during hypoxia. The effects of inflation were not changed by NO synthase blockade in either rat group. Pulmonary hypertensive effects of inflation in chronically hypoxic rats can be attributed to vascular remodelling.