Decreased inhibition by gravidin of arachidonate release from transformed compared to nontransformed cells.
1. Gravidin (a phospholipase A2 inhibitor) reduced the release of arachidonic acid from human lymphocytes by 51% at 10(-8) M. 2. Under normal culture conditions, nanomolar gravidin caused a significant reduction in the release of free arachidonic acid from human lymphocytes or nontransformed fibroblasts but in transformed cells, nanomolar gravidin was ineffective. 3. Inhibition of arachidonate release appeared to be related to rate of growth as inhibitory effects of gravidin on Jurkat cells and HL-29 cells could be observed if the cells were cultured under conditions where DNA synthesis was low. 4. The reported disparate effects of lipocortin on cell phospholipase A2 activity may be reconciled if DNA synthesis is investigated.
Wilson
T
T
Department of Cellular and Molecular Biology, University of Auckland, New Zealand.
Ralph
R K
RK
Ganendren
R
R
D016718:Arachidonic Acid / Q000378:metabolism*; D002478:Cells, Cultured; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D008213:Lymphocyte Activation / Q000502:physiology*; D008214:Lymphocytes / Q000187:drug effects / Q000378:metabolism*; D010741:Phospholipases A / Q000037:antagonists & inhibitors*; D054467:Phospholipases A2; D011257:Pregnancy Proteins / Q000494:pharmacology*; D013936:Thymidine / Q000378:metabolism
D011257:Pregnancy Proteins; C058795:gravidin; D016718:Arachidonic Acid; D010741:Phospholipases A; D054467:Phospholipases A2; D013936:Thymidine