Effect of p-chloroamphetamine on calcium movement and viability in renal tubular cells

摘要

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 (>= 10 mu M) 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 mu M 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. (c) 2005 Elsevier Inc. All rights reserved.