Neutrophil lipoxygenase activation and leukosequestration in postischemic myocutaneous flaps: role of LTB4.

Abstract

Reperfusion of ischemic tissues leads to eicosanoid- and polymorphonuclear leukocyte (PMN)-dependent injury. The present experiments were undertaken to examine the effect of myocutaneous flap ischemia-reperfusion on neutrophil 5-lipoxygenase activity and to define the role of leukotriene B4 (LTB4) in postischemic PMN infiltration into such composite tissue grafts. Anesthetized Yorkshire pigs underwent 6 h of rectus abdominis myocutaneous flap ischemia or sham ischemia, and LTB4 generation was measured in calcium ionophore-stimulated neutrophils isolated from the circulation. At 30 min of reperfusion, neutrophil generation of LTB4 increased from a baseline value of 31.0 +/- 6.8 to 98.5 +/- 5.1 ng/5 x 10(6) PMN (P < 0.01) and was significantly greater than those neutrophils isolated from animals subjected to sham ischemia and reperfusion (54.3 +/- 4.1 ng/5 x 10(6) PMN; P < 0.01). Pretreatment of animals with the LTB4-receptor antagonist, SC-41930 (n = 5), significantly attenuated reperfusion-associated 5-lipoxygenase activation (60.3 +/- 11.6 ng LTB4/5 x 10(6) PMN; P < 0.01), suggesting the presence of a positive feedback mechanism for eicosanoid biosynthesis.(ABSTRACT TRUNCATED AT 250 WORDS)

• Authors: R E Kirschner, J J Chiao, B S Fyfe, L A Hoffman, J M Davis, G A Fantini
• Journal: The American journal of physiology (Am J Physiol) Vol. 268 Issue 6 Pt 2 Pg. H2167-74 (Jun 1995) ISSN: 0002-9513 [Print] United States
• PMID: 7611467 (Publication Type: Journal Article)

Chemical References

• Benzopyrans
• Lipoxygenase Inhibitors
• Receptors, Leukotriene B4
• SC 41930
• Leukotriene B4
• Arachidonate 5-Lipoxygenase

Topics

• Animals
• Arachidonate 5-Lipoxygenase (blood)
• Benzopyrans (pharmacology)
• Blood Pressure
• Enzyme Activation
• Female
• Heart Rate
• Ischemia (blood, physiopathology)
• Leukocyte Count (drug effects)
• Leukotriene B4 (antagonists & inhibitors)
• Lipoxygenase Inhibitors
• Muscle, Skeletal (blood supply, pathology)
• Neutrophils (drug effects, enzymology, physiology)
• Receptors, Leukotriene B4 (antagonists & inhibitors)
• Reperfusion
• Skin (blood supply)
• Surgical Flaps
• Swine