GEA3162 stimulates Ca2+ entry in neutrophils.
We showed that 5-amino-3-(3,4-dichlorophenyl)1,2,3,4-oxatriazolium (GEA3162), a lipophilic nitric oxide (NO)-releasing agent, induced Ca(2+) entry into rat neutrophils in a concentration-dependent manner, whereas the guanylyl cyclase inhibitors, 6-anilino-5,8-quinolinequinone (LY83583) and 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), had no effect on GEA3162-induced response. The GEA3162-induced Ca(2+) entry was not observed in a Ca(2+)-free medium. GEA3162 did not potentiate but reduced the store-emptying activated Ca(2+) entry caused by cyclopiazonic acid. Stimulation of cells with GEA3162 in the absence of extracellular Ca(2+) followed by addition of cations showed that only Ca(2+) but not Ba(2+) and Sr(2+) entry occurs. Store-operated Ca(2+) entry was sensitive to La(3+) and Ni(2+) inhibition, whereas the GEA3162-induced Ca(2+) entry was sensitive to La(3+) but resistant to Ni(2+). cis-N-(2-Phenylcyclopentyl)azacyclotridec-1-en-2-amine (MDL-12,330A) and calyculin A diminished the Ca(2+) entry activated by cyclopiazonic acid as well as by GEA3162. In contrast, 2-aminoethyldiphenyl borate (2-APB) diminished cyclopiazonic acid-but enhanced GEA3162-induced [Ca(2+)](i) change. Genistein effectively attenuated the cyclopiazonic acid-but slightly inhibited GEA3162-induced [Ca(2+)](i) change. Application of neomycin and high extracellular Ca(2+) concentration did not induce [Ca(2+)](i) rise. These data suggest that GEA3162 induced Ca(2+) entry and regulated Ca(2+) signal, through direct protein thiol oxidation. The action of GEA3162 demonstrates characteristics that distinguish it from the store-operated mechanism in neutrophils and therefore is likely to represent an entirely distinct pathway. Extracellular Ca(2+)-sensing receptor is not existing in neutrophils.
Wang
Jih-Pyang
JP
Department of Education and Research, Taichung Veterans General Hospital, Taichung, Taiwan, ROC. w1994@vghtc.vghtc.gov.tw
D000067956:Adenylyl Cyclase Inhibitors; D000818:Animals; D001464:Barium / Q000378:metabolism; D001896:Boron Compounds / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism* / Q000494:pharmacology; D020013:Calcium Signaling / Q000187:drug effects; D000252:Calcium-Transporting ATPases / Q000037:antagonists & inhibitors; D002463:Cell Membrane Permeability / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D019833:Genistein / Q000494:pharmacology; D007097:Imines / Q000494:pharmacology; D007211:Indoles / Q000494:pharmacology; D008345:Manganese / Q000378:metabolism; D008387:Marine Toxins; D009504:Neutrophils / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D020030:Nitric Oxide Donors / Q000494:pharmacology*; D010080:Oxazoles / Q000494:pharmacology; D010749:Phosphoprotein Phosphatases / Q000037:antagonists & inhibitors; D051381:Rats; D017207:Rats, Sprague-Dawley; D026403:S-Nitrosothiols / Q000378:metabolism; D013324:Strontium / Q000378:metabolism; D014230:Triazoles / Q000494:pharmacology*
D000067956:Adenylyl Cyclase Inhibitors; D001896:Boron Compounds; D004791:Enzyme Inhibitors; D007097:Imines; D007211:Indoles; D008387:Marine Toxins; D020030:Nitric Oxide Donors; D010080:Oxazoles; D026403:S-Nitrosothiols; D014230:Triazoles; D001464:Barium; D008345:Manganese; C059041:calyculin A; C014925:RMI 12330A; C082874:GEA 3162; D019833:Genistein; C109986:2-aminoethoxydiphenyl borate; D010749:Phosphoprotein Phosphatases; D000252:Calcium-Transporting ATPases; D002118:Calcium; C000543:cyclopiazonic acid; D013324:Strontium