Facilitation of calcium influx by propylene glycol through the voltage-dependent calcium channels in PC12 cells
Hattori, T.; Maehashi, H.
Research Communications in Molecular Pathology and Pharmacology 105(3): 179-184
1999
ISSN/ISBN: 1078-0297 PMID: 10954124 Document Number: 498997
Propylene glycol (PG) raises an intracellular calcium concentration ([Ca2+]i) in PC12 cells. The present study has been undertaken to examine whether or not the voltage-dependent Ca2+ channels are involved in the PG-induced rise in [Ca2+]i and, if so, to determine which types participate in it. CdCl2 (50 micro M) and the Ca2+ -free saline depressed the action of PG (0.5 - 10 %v/v)-induced [Ca2+]i rise. Although NiCl2 (50 micro M) at the same concentration as CdCl2, and omega-agatoxin (50 and 300 nM) had no effect on the PG-induced [Ca2+]i rise, each of omega-conotoxin (1 micro M), nifedipine (10 micro M), nicardipine (10 micro M), varapamil (10 micro M) and diltiazem (10 micro M) significantly decreased it. Electrical stimulation and Bay K 8644 (1 micro M) enhanced the PG-induced [Ca2+]i rise. The second phase of the [Ca2]i rise was fallen fast by nicardipine (10 micro M), but not by omega-conotoxin (1 micro M). The results obtained suggested that the Ca2+ influx through the L- and N-type Ca2+ channels are involved in the PG-induced [Ca2+]i rise.