Effect of NPC-15199 on Ca2+ levels in renal tubular cells.
In Madin-Darby canine kidney (MDCK) cells, effect of NPC-15199 on intracellular Ca2+ concentration ([Ca2+]i) was investigated by using fura-2. NPC-15199 (100-1000 microM) caused a rapid and sustained increase of [Ca2+]i in a concentration-dependent manner (EC50=500 microM). NPC-15199-induced [Ca2+]i rise was prevented by 70% by removal of extracellular Ca2+, but was not changed by dihydropyridines, verapamil and diltiazem. In Ca2+-free medium, carbonylcyanide m-chlorophenylhydrazone (CCCP; 2 microM), a mitochondrial uncoupler, and thapsigargin (1 microM), an inhibitor of the endoplasmic reticulum (ER) Ca2(+)-ATPase, caused a monophasic [Ca2+]i rise, respectively, after which the increasing effect of NPC-15199 (1 mM) on [Ca2+]i was substantially attenuated; also, pretreatment with NPC-15199 abolished CCCP- and thapsigargin-induced [Ca2+]i rises. U73122, an inhibitor of phospholipase C, [corrected] abolished 10 microM ATP (but not 1 mM NPC-15199)-induced [Ca2+]i rise. These results suggest that NPC-15199 rapidly increases [Ca2+]i by stimulating both extracellular Ca2+ influx and intracellular Ca2+ release via as yet unidentified mechanism(s).
Jan
Chung-Ren
CR
Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan, Republic of China.
Jiann
Bang-Ping
BP
Chang
Hong-Tai
HT
Yu
Cha-Chen
CC
Lu
Yih-Chau
YC
Yeh
Jeng-Hsien
JH
Chen
Wei-Chun
WC
Law
Yee-Ping
YP
Huang
Jong-Khing
JK
D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002118:Calcium / Q000493:pharmacokinetics*; D002460:Cell Line; D005449:Fluorenes / Q000494:pharmacology*; D005456:Fluorescent Dyes; D016257:Fura-2; D007684:Kidney Tubules / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D007930:Leucine / Q000031:analogs & derivatives* / Q000494:pharmacology*; D008345:Manganese / Q000494:pharmacology; D010738:Type C Phospholipases / Q000378:metabolism
D005449:Fluorenes; D005456:Fluorescent Dyes; C082231:N-(fluorenyl-9-methoxycarbonyl)leucine; D008345:Manganese; D010738:Type C Phospholipases; D007930:Leucine; D002118:Calcium; D016257:Fura-2