Ischemia Induced Neutrophil Activation and Diapedesis is Lipoxygenase Dependent.

Abstract

Ischemia and reperfusion lead to eicosanoid and neutrophil (PMN) dependent injury. This study tests the role of ischemia induced lipoxygenase activity in mediating PMN activation and diapedesis. Anesthetized rabbits (n = 8) underwent 3 h of bilateral hindlimb ischemia. At 10 min of reperfusion, leukotriene (LT)B sub 4 levels in femoral venous effluent were 0.49 +/- 0.05 ng/ml compared to 0.04 +/- 0.07 ng/ml in sham animals (n = 10) (p<0.05). Intracellular H2O2 production of circulating PMN assayed flow cytometrically by dichlorofluorescein (DCF) oxidation, increased from a preischemic value of 74 +/- 14 fentamoles (fM) DCF/cell to 135 +/- 8 fM DCF/cell (p<0.05). PMN were treated with phorbol myristate acetate (PMA) 10(exp -7)M. In contrast to a 162% increase in H2O2 production prior to ischemia, PMN at 10 min of reperfusion had an enhanced response to PMA of 336% (p<0.05). Addition of authentic LTB sub 4 (0.5 ng/ml) to PMN from sham animals led to their activation, manifested by an oxidative burst, 127 +/- 12 fM DCF/cell and an enhanced response of 337% to PMA stimulation. To study diapedesis, plasma collected at 10 min of reperfusion was introduced into plastic chambers taped atop skin abrasions in rabbits (n = 8). After 3 h, 1610 +/- 246 PMN/mm(exp 3) accumulated and LTB sub 4 levels in blister fluid were 0.83 +/- 0.03 ng/ml, higher than values of 44 +/- 23 PMN/mm(exp 3) (p<0.05) and 0.04 +/- 0.03 ng LTB sub 4/ml (p<0.05) with saline, and 68 +/- 16 PMN/mm(exp 3) (p<0.05) and 0.19 +/- 0.02 ng/ml (p<0.05) with non-ischemic plasma. The introduction of LTB sub 4, 3.3 ng/ml into the chambers resulted in an accumulation of 536 +/- 352 PMN/mm(exp 3) (p<0.05). Pre-treatment of animals prior to hindlimb ischemia (n = 5) with the lipoxygenase inhibitor diethylcarbamazine abolished PMN activation (51 +/- 12 fM DCF/cell) and ischemic plasma induced diapedesis into the plastic chamber (38 +/- 18 PMN/mm(exp 3)).

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Document Details

Document Type
Technical Report
Publication Date
Apr 17, 1991
Accession Number
ADA360203

Entities

People

  • Gideon Goldman
  • Ian S. Paterson
  • Joseph M. Klausner
  • Richard Welbourn

Organizations

  • Boston University

Tags

Communities of Interest

  • Biomedical

DTIC Thesaurus Topics

  • Animal Structures
  • Assays
  • Biological Sciences
  • Blood
  • Blood Cells
  • Blood Flow
  • Cardiovascular System
  • Cells
  • Chemistry
  • Classification
  • Enzyme Inhibitors
  • Health Services
  • Inhibitors
  • Laboratory Animals
  • Leukocytes
  • Security
  • Vena Cava

Fields of Study

  • Biology
  • Medicine

Readers

  • Cardiovascular Physiology
  • Immunology and Pathology