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Query: UMLS:C0242706 (hyperoxia)
 5,219 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Experimental pneumonia induced by intratracheal application of carrageenan or paraquat increases the functional residual lung capacity (FRC) in rats. The mechanism of this increase is not clear, but a decrease in PO(2) may be involved. To test this possibility, we attempted to eliminate the PO(2) decrease in carrageenan-treated rats by exposing them to hyperoxia. Animals of the first group were exposed to 7 days of hyperoxia (F(I)O(2) 0.78-0.84, group Car+O(2)) after intratracheal application of carrageenan (0.5 ml of 0.7 % carrageenan in saline), whereas animals of the second group were given the same dose of carrageenan but breathed air (group Car+A). The third group of rats was kept for seven days in hyperoxia (group O(2)) and the fourth group served as controls (C). The animals were then anesthetized and intubated and their ventilatory parameters and FRC were measured during air breathing. Carrageenan application induced a FRC increase (Car+A 2.0+/-0.2 ml, C 1.6+/-0.1 ml), which was not seen in carrageenan-treated rats exposed to hyperoxia (Car+O(2) 1.6+/-0.1 ml). Hyperoxia alone did not affect the value of FRC (O(2) 1.5+/-0.1 ml). These results support the hypothesis that a decrease in PO(2) plays an important role in the carrageenan-induced increase of FRC in rats.
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PMID:Hyperoxia prevents carrageenan-induced enlargement of functional residual lung capacity in rats. 1464 Aug 98

Although nitrated proteins have been repeatedly used as markers of lung injury, little is known about their formation and metabolism under hyperoxia. We therefore measured 3-nitrotyrosine (3NTYR) concentrations in lung tissue and serum of rats with carrageenan-induced pneumonia exposed to hyperoxia. Twenty-nine Wistar male rats were assigned to one of 4 groups. Two experimental groups were treated by intratracheal application of carrageenan (0.5 ml of 0.7 % solution) and then one was exposed to hyperoxia for 7 days (FIO2 0.8), the other to air. Rats of two control groups breathed either hyperoxic gas mixture or air for 7 days. At the end of exposure the ventilation was determined in anesthetized, intubated animals in which 3NTYR concentrations were measured in the lung tissue and nitrites and nitrates (NOx) were estimated in the serum. Carrageenan instillation increased 3NTYR concentrations in lung tissue (carrageenan-normoxic group 147+/-7 pmol/g protein, control 90+/-10 pmol/g protein) and NOx concentration in the serum (carrageenan-normoxic group 126+/-13 ppb, control 78+/-9 ppb). Hyperoxia had no effect on lung tissue 3NTYR concentration in controls (control-hyperoxic 100+/-14 pmol/g protein) but blocked the increase of lung tissue 3NTYR in carrageenan-treated rats (carrageenan-hyperoxic 82+/-13 pmol/g protein), increased NOx in serum (control-hyperoxic 127+/-19 ppb) and decreased serum concentration of 3NTYR in both hyperoxic groups (carrageenan-hyperoxic 51+/-5 pmol/g protein, control-hyperoxic 67+/-7 pmol/g protein, carrageenan-normoxic 82+/-9 pmol/g protein, control 91+/-7 pmol/g protein). The results suggest that hyperoxia affects nitration of tyrosine residues, probably by increasing 3NTYR degradation.
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PMID:Hyperoxia attenuated nitrotyrosine concentration in the lung tissue of rats with experimental pneumonia. 1547 26