Facilitation of calcium influx by propylene glycol through the voltage-dependent calcium channels in PC12 cells.
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.
Hattori
T
T
Department of Dental Pharmacology, Matsumoto Dental University, Shiojiri, Japan. hattori@po.mdu.ac.jp
Maehashi
H
H
D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester / Q000494:pharmacology; D000818:Animals; D019256:Cadmium Chloride / Q000494:pharmacology; D002121:Calcium Channel Blockers / Q000494:pharmacology; D015220:Calcium Channels / Q000145:classification / Q000187:drug effects* / Q000378:metabolism*; D020013:Calcium Signaling / Q000187:drug effects*; D004558:Electric Stimulation; D009529:Nicardipine / Q000494:pharmacology; D016716:PC12 Cells; D019946:Propylene Glycol / Q000494:pharmacology*; D051381:Rats; D020960:omega-Conotoxins / Q000494:pharmacology
D002121:Calcium Channel Blockers; D015220:Calcium Channels; D020960:omega-Conotoxins; D019946:Propylene Glycol; D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; D009529:Nicardipine; D019256:Cadmium Chloride