Lead reduces depolarization-induced calcium entry in cultured DRG neurons without crossing the cell membrane: fura-2 measurements. Academic Article uri icon

Overview

abstract

  • 1. Cultured dorsal root ganglion of rat pups were depolarized by exposure to 50 mM K+ and the rise of [Ca2+]i was measured using fura-2 as an indicator. 2. Lead in the extracellular solution reduced the rise of [Ca2+]i in a concentration-dependent manner, with a threshold concentration of 0.25 microM. More than 80% of the calcium entry was prevented by approximately 5 microM lead. The IC50 and the Hill coefficient were 3.1 microM and 1, respectively. 3. This effect was considered to be due to a reduction of VACCCs, since applications of NMDA did not result in any rise of [Ca2+]i. 4. Since Pb2+ itself changes the fura-2 signal in a typical and characteristic manner, fura-2 is also an indicator for Pb2+. No changes in fura-2 signals were detected when lead (5 microM) was applied for several minutes in the absence of calcium, indicating that Pb2+ did not enter the cells. 5. Thus it is concluded that lead prevents calcium entry by reducing VACCCs but does not cross the cell membrane itself.

publication date

  • June 1, 1997

Research

keywords

  • Calcium
  • Calcium Channels
  • Cell Membrane
  • Ganglia, Spinal
  • Lead

Identity

Scopus Document Identifier

  • 0030915161

PubMed ID

  • 9187487

Additional Document Info

volume

  • 17

issue

  • 3