[Regulation by the protein kinase C activator phorbol ester of calcium channels in polymorphonuclear leukocytes].
The Quin fluorescence in gamma-hexachlorocyclohexane-stimulated polymorphonuclear leukocytes is rapidly increased, which points to the increase in Ca2+in concentration during leukotriene B4 synthesis in leukocytes. An addition of EGTA and calcium antagonists (nifedipine, verapamil, diltiazem) to cell suspensions does not affect the basal level of internal Ca2+ but results in the inhibition of the gamma-hexachlorocyclohexane-induced Ca2+ increase. Two mechanisms of calcium homeostasis regulation in neutrophils are proposed. One of them, cAMP regulation, is coupled with a potent inhibiting effect of prostacyclin, an adenylate cyclase activator, on Ca2+in increase in stimulated neutrophils. The other one is the activation of protein kinase C catalyzed by 4 beta-phorbol-12 beta-myristate-13 alpha-acetate. The experimental results suggest that such an activation blocks Ca2+ influx into the cells via the closure of Ca2+ channels. The synergism of action of the above mechanisms in the regulation of calcium homeostasis in neutrophils is demonstrated.
Grigorian
M R
MR
Akopov
S E
SE
Gabrielian
E S
ES
D000634:Aminoquinolines; D002118:Calcium / Q000097:blood*; D015220:Calcium Channels / Q000187:drug effects / Q000378:metabolism*; D000242:Cyclic AMP / Q000378:metabolism; D004789:Enzyme Activation; D005456:Fluorescent Dyes; D001556:Hexachlorocyclohexane / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D009504:Neutrophils / Q000378:metabolism*; D011493:Protein Kinase C / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
D000634:Aminoquinolines; D015220:Calcium Channels; D005456:Fluorescent Dyes; D001556:Hexachlorocyclohexane; D000242:Cyclic AMP; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate; C035739:Quin2; D002118:Calcium
Reguliatsiia aktivatorom proteinkinazy C forbolovym éfirom kal'tsievykh kanalov polimorfno-iadernykh leĭkotsitov.