Carrageenan-stimulated release of arachidonic acid and of lactate dehydrogenase from rat pleural cells

Biochem Pharmacol. 1987 Jul 15;36(14):2405-13. doi: 10.1016/0006-2952(87)90610-1.


Cells isolated from the rat pleural cavity consist mainly of macrophages, mast cells, eosinophils, and lymphocytes. Isolated pleural cells labeled with [14C]arachidonic acid released appreciable amounts (approximately 12%) of radiolabel upon exposure to pharmacological concentrations of carrageenan (1-100 micrograms/ml). The release of radiolabel was decreased by an inhibitor of phospholipase A2 (p-bromophenacyl bromide) but not by an inhibitor of arachidonate cyclooxygenase (indomethacin). The released products were arachidonic acid and, to a much lesser extent, prostaglandin E2 and leukotriene C4. The release of radiolabel was associated with release of cytosolic lactate dehydrogenase over the same range of carrageenan concentrations. Time-course studies indicated that release of radiolabel preceded that of lactate dehydrogenase. Since p-bromophenacyl bromide blocked stimulated release of radiolabel but did not prevent release of lactate dehydrogenase, it is unlikely that increase in arachidonate causes carrageenan-induced cell damage. Nevertheless, the question of whether the activation of phospholipase A2 in the pleural cells, most probably the macrophages, was sufficient to initiate the carrageenan-induced inflammatory response requires further study. Cytotoxicity which was apparent with as little as 5 micrograms/ml of carrageenan, may have been a significant consequence of carrageenan action.

MeSH terms

  • Acetophenones / pharmacology
  • Animals
  • Arachidonic Acid
  • Arachidonic Acids / metabolism*
  • Carrageenan / pharmacology*
  • Cells, Cultured
  • Cyclooxygenase Inhibitors
  • Dinoprostone
  • Indomethacin / pharmacology
  • L-Lactate Dehydrogenase / metabolism*
  • Lipid Metabolism
  • Phospholipases A / antagonists & inhibitors
  • Phospholipases A2
  • Pleura / cytology
  • Pleura / drug effects*
  • Pleura / metabolism
  • Prostaglandins E / metabolism
  • Rats
  • SRS-A / metabolism
  • Secretory Rate / drug effects


  • Acetophenones
  • Arachidonic Acids
  • Cyclooxygenase Inhibitors
  • Prostaglandins E
  • SRS-A
  • Arachidonic Acid
  • Carrageenan
  • L-Lactate Dehydrogenase
  • Phospholipases A
  • Phospholipases A2
  • Dinoprostone
  • 4-bromophenacyl bromide
  • Indomethacin