Characteristics of the K-252a-induced increase in calcium uptake in PC12 cells

✍ Scribed by B. Nikodijevic; M. Aschkenasy; G. Dickens; C. Lachance; Gordon Guroff

• Publisher: John Wiley and Sons
• Year: 1995
• Tongue: English
• Weight: 547 KB
• Volume: 40
• Category: Article
• ISSN: 0360-4012
• DOI: 10.1002/jnr.490400408

✦ Synopsis

K-252a treatment produced a 3040% increase in the uptake of radioactive calcium by PC12 cells within 3 4 minutes. The increase in uptake was partially blocked by inhibitors of voltage-operated calcium channels, such as nifedipine, but not by inhibitors of receptor-operated calcium channels, such as nickel or suramin. Introduction of phosphatase 2A into the cells completely blocked the effect of K-252a. Longterm treatment of the cells with either K-252a or with nerve growth factor blocked the subsequent actions of either K-252a or nerve growth factor on calcium uptake, but neither altered the subsequent action of the L-channel agonist Bay K 8644 on calcium uptake. Calcium uptake was not stimulated by K-252a in PClZnnr, cells that have little or no high-affinity nerve growth factor receptors; cells expressing increased levels of high-affinity nerve growth factor receptors showed a response to K-252a comparable to that seen in parent PC12. The data suggest that the increased uptake of radioactive calcium produced by K-252a is mediated by a mechanism very similar to that serving the increased calcium uptake produced by nerve growth factor.