Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0242706 (hyperoxia)
 5,219 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Lung injury induced by 100% O2 over 6 days is characterized by markedly less alveolar fibrin and rare hyaline membranes in premature versus adult baboons. To determine the mechanism(s) underlying alveolar fibrin deposition in the evolution of hyaline membrane disease (HMD) through diffuse alveolar damage (DAD) and bronchopulmonary dysplasia (BPD), we measured procoagulant and fibrinolytic activities in lung lavage of premature baboons with HMD, those treated with 100% O2 for 6 days (DAD) or for 7 days followed by 14 days 80% O2 (BPD). Lavage procoagulant activity, mainly due to tissue factor associated with Factor VII, was increased by hyperoxia. Plasminogen-dependent fibrinolytic activity, due to both tissue plasminogen activator and urokinase, was stable or increased after hyperoxia. Plasminogen activator inhibitor 1 (PAI-1) was detectable in lavage of animals with HMD but not those with evolving DAD or BPD. Antiplasmin activity was stable or decreased. Although plasminogen was undetectable in lavage, D-dimer was increased in lavage of the groups exposed to hyperoxia versus HMD. The defect in plasminogen activator activity in lavage fluids of adult baboons with DAD induced by O2 does not occur in premature baboons with HMD, evolving DAD, or BPD. Expression of fibrinolytic activity in the lower respiratory tract of premature baboons is dependent on local access to plasminogen, which is present in relatively low concentrations in plasma of these animals.
 ...
PMID:Pathways of fibrin turnover in lavage of premature baboons with hyperoxic lung injury. 811 20

The aims of this study were to examine the effect of oxygen, in the presence or absence of exogenous growth factors, on the release of plasminogen activators and plasminogen activator inhibitor-1 by cultured human retinal pigment epithelial cells. Antigen and activity levels of urokinase, tissue plasminogen activator and plasminogen activator inhibitor were measured in conditioned media after cells were exposed to three different oxygen environments: hypoxia, normoxia and hyperoxia. Overall proteolytic balance was determined by zymography. The effects of exogenous basic fibroblast growth factor and transforming growth factor-beta were also examined. it was found that retinal pigment epithelial cells released urokinase, tissue plasminogen activator and plasminogen activator inhibitor in measurable quantities. After 48 h, urokinase levels were highest at normoxia, reaching 7.2ng/10(6) cells (+/-2.0 SEM), whereas plasminogen activator inhibitor 1 levels were highest at hyperoxia, reaching 67.5ng/10(6) cells (+/-3.7 SEM). Tissue plasminogen activator levels were minimal (<0.5ng/10(6) cells) and unaffected by both oxygen and growth factors. Overall proteolytic activity was also greatest at normoxia. Fibroblast growth factor stimulated urokinase production dose-dependently, but plasminogen activator inhibitor only minimally. Transforming growth factor-beta stimulated plasminogen activator inhibitor production dose-dependently but urokinase only at higher concentrations. These results suggest that both oxygen tension and growth factors may interact to modulate the proteolytic properties of the human retinal pigment epithelium.
 ...
PMID:Oxygen modulates the release of urokinase and plasminogen activator inhibitor-1 by retinal pigment epithelial cells. 1131 55