Inhibitors of arachidonic acid metabolism eliminate the increase in cytosolic free calcium induced by the mitogen concanavalin A in rat thymocytes.
Using inhibitors of arachidonic acid (AA) metabolism, the possible involvement of AA products in the generation of [Ca2+]i and the pHi rise induced by the mitogen concanavalin A (Con A) in rat thymocytes has been studied. The lipoxygenase inhibitor nordihydroguaiaretic acid (NDGA, 10 microM) and the phospholipase A2 inhibitor bromophenacyl bromide (10 microM) eliminated the [Ca2+]i signal induced by Con A; the cyclooxygenase blocker indomethacin also inhibited it. However, neither NDGA nor indomethacin suppressed the pHi rise stimulated by Con A. Exogenous AA induced an increase in [Ca2+]i but not in the pHi. These results indicate that AA metabolites, probably of the lipoxygenase pathway, take part in the generation of the [Ca2+]i response to the mitogen. In contrast, they appear not to be involved in the pHi rise evoked by Con A.
Gukovskaya
A S
AS
Institute of Biological Physics, USSR Academy of Sciences, Pushchino, Moscow Region.
Pulido
H A
HA
Zinchenko
V P
VP
Evtodienko YuV
D000098:Acetophenones / Q000494:pharmacology; D000818:Animals; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D002396:Catechols / Q000494:pharmacology*; D003208:Concanavalin A / Q000494:pharmacology*; D003600:Cytosol / Q000187:drug effects / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D007213:Indomethacin / Q000494:pharmacology*; D007700:Kinetics; D009637:Masoprocol / Q000494:pharmacology*; D010741:Phospholipases A / Q000037:antagonists & inhibitors; D054467:Phospholipases A2; D051381:Rats; D011919:Rats, Inbred Strains; D013601:T-Lymphocytes / Q000187:drug effects / Q000378:metabolism*
D000098:Acetophenones; D001095:Arachidonic Acids; D002396:Catechols; D003208:Concanavalin A; D016718:Arachidonic Acid; D009637:Masoprocol; D010741:Phospholipases A; D054467:Phospholipases A2; C006821:4-bromophenacyl bromide; D007213:Indomethacin