Nifedipine, verapamil and diltiazem block shock-wave-induced rises in cytosolic calcium in MDCK cells.

Nifedipine and verapamil have been shown previously to protect against renal function alterations induced by shock wave lithotripsy (SWL) in humans and rats; however, the mechanism is unclear. This study was aimed to examine whether these drugs could protect cultured kidney cells following shock wave exposure (SWE). The effect of nifedipine, verapamil and diltiazem on Madin Darby canine kidney (MDCK) cells following SWE was examined by determining the release of glutamate oxalactate transferase (GOT) and lactate dehydrogenase (LDH) in cell suspensions; and also cytosolic Ca2+ concentration ([Ca2+]i). Immediately after SWE, there was a transient release of GOT and LDH (16% and 4 fold, respectively). In contrast, [Ca2+]i measured within 1-6 hr after SWE gradually increased by 15-156%. The Ca2+ entry blockers (1 or 10 microM) failed to inhibit the enzyme release; however, they abolished the progressive rises in [Ca2+]i. The Ca2+ entry blockers may protect the cells from damage of SWE via maintaining a low resting [Ca2+]i.