Effect of p-chloroamphetamine on calcium movement and viability in renal tubular cells.
In Madin-Darby canine kidney (MDCK) cells, the effect of p-chloroamphetamine, a neurotoxin that depletes intracellular serotonin, on intracellular Ca2+ concentration ([Ca2+]i) and viability was measured by using the Ca2+-sensitive fluorescent dye fura-2 and the viability detecting fluorescent dye tetrazolium. p-Chloroamphetamine (> or = 10 microM) caused a rapid rise of [Ca2+]i in a concentration-dependent manner. p-Chloroamphetamine-induced [Ca2+]i rise was partly reduced by removal of extracellular Ca2+. p-Chloroamphetamine-induced extracellular Ca2+ influx was also suggested by Mn2+ influx-induced fura-2 fluorescence quench. In Ca2+-free medium, thapsigargin, an inhibitor of the endoplasmic reticulum Ca2+-ATPase, caused a monophasic [Ca2+]i rise, after which p-chloroamphetamine failed to increase [Ca2+]i; also, pretreatment with p-chloroamphetamine reduced 50% of thapsigargin-sensitive Ca2+ stores. U73122, an inhibitor of phospholipase C, abolished ATP (but not p-chloroamphetamine)-induced [Ca2+]i rise. Overnight incubation with 1-500 microM p-chloroamphetamine decreased cell viability. These findings suggest that p-chloroamphetamine evokes a rapid increase in [Ca2+]i in renal tubular cells by stimulating both extracellular Ca2+ influx and intracellular Ca2+ release, and is cytotoxic.
Jan
Chung-Ren
CR
Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan 813. crjan@isca.vghks.gov.tw
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000187:drug effects*; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects*; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D005456:Fluorescent Dyes / Q000378:metabolism; D016257:Fura-2 / Q000378:metabolism; D007684:Kidney Tubules / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D018490:Serotonin Agents / Q000494:pharmacology*; D013778:Tetrazolium Salts / Q000378:metabolism; D013997:Time Factors; D010133:p-Chloroamphetamine / Q000494:pharmacology*
C110656:2-(4-iodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium; D005456:Fluorescent Dyes; D018490:Serotonin Agents; D013778:Tetrazolium Salts; D010133:p-Chloroamphetamine; D002118:Calcium; D016257:Fura-2