Effects of nitrendipine on the voltage-sensitive calcium channel in mammalian sensory neurons

✍ Scribed by M. J. Litzinger; P. G. Nelson; R. Y. K. Pun

• Publisher: John Wiley and Sons
• Year: 1985
• Tongue: English
• Weight: 437 KB
• Volume: 14
• Category: Article
• ISSN: 0360-4012
• DOI: 10.1002/jnr.490140404

✦ Synopsis

Wc cxamincd the ability of nitrendipine, a calcium antagonist believed to block the voltage-sensitive calcium channcls in a number of excitable membranes, to affect the calcium spike duration and rate of rise (DviDt) in 4-week-old cultured mouse dorsal root ganglion neurons. Concentrations of 10 nM-1 .O pM nitrendipine reduced but did not eliminate calcium spike as measured by the rate of rise. Thcsc results were obtained at either 22" or 37°C in solutions containing 5 mM calcium. A similar lack of total block was seen with prolonged incubation in sodium-free recording media containing 1 pM tetrodotoxin (TTX), 1.8 mM calcium, and 1 pM nitrendipine. Calcium spike duration was affected in an inconsistent manner by nitrendipine and other 1,4 dihydropyridincs. Cobalt (10 mM) totally blocked the voltage-dependent calcium mechanism as measured by cither the spike duration or the rate of rise. We conclude that calcium influx through the voltage-sensitive calcium channel in mouse dorsal root ganglion neurons is not blocked by even high concentrations of nitrendipine.