Effects of oxygen radicals on cysteinyl leukotriene metabolism and pulmonary circulation in young pigs.
The effects of oxygen radicals, generated by the hypoxanthine-xanthine oxidase (XO) system, on pulmonary circulation and release of cysteinyl-containing leukotrienes (LTs) were studied in pigs after XO infusion into the right atrium. A 2.3-fold increase in pulmonary vascular resistance (PVR) (p < 0.05 vs. baseline) and a 2.1-fold increase in LT release (p < 0.05 vs. baseline) was observed. Pretreatment with indomethacin and allopurinol attenauted the vascular response (p < 0.01 and p < 0.05 vs. XO), and the LT release was inhibited by allopurinol and catalase (p < 0.01 and p < 0.02 vs. XO). We conclude that oxygen radicals stimulate lipoxygenase metabolism. This coincides with the observed increase in PVR, however, no causal relationship can be derived from the data presented.
Sanderud
J
J
Institute for Surgical Research, University of Oslo, Rikshospitalet, Norway.
Kumlin
M
M
Granström
E
E
Saugstad
O D
OD
D000818:Animals; D003545:Cysteine / Q000378:metabolism; D005260:Female; D005609:Free Radicals; D019271:Hypoxanthine; D007042:Hypoxanthines / Q000097:blood; D015289:Leukotrienes / Q000378:metabolism*; D008297:Male; D009569:Nitric Oxide / Q000502:physiology; D010100:Oxygen / Q000378:metabolism*; D011652:Pulmonary Circulation; D013552:Swine; D014655:Vascular Resistance; D014969:Xanthine Oxidase / Q000494:pharmacology
D005609:Free Radicals; D007042:Hypoxanthines; D015289:Leukotrienes; D019271:Hypoxanthine; D009569:Nitric Oxide; D014969:Xanthine Oxidase; D003545:Cysteine; D010100:Oxygen