The NMDA type glutamate receptors expressed by primary rat osteoblasts have the same electrophysiological characteristics as neuronal receptors
Abstract
Cells of mammalian bone express glutamate receptors. Functional N-methyl-D-aspartate (NMDA) receptors have been demonstrated in human, osteoblastic MG-63 cells, but currents in these cells, unlike those of mammalian neurons, are blocked by Mg(2+) in a voltage-insensitive manner. Differences between the characteristics of NMDA currents in bone cells and in neurons may reflect molecular variation of the receptors or associated molecules, with implications for the role(s) of glutamate in these different tissues and for targeting of ligands/antagonists. To determine whether NMDA receptors in primary bone cells are functional, and whether the currents carried by these receptors resemble those of MG-63 cells or those of mammalian neurons, we have applied the whole cell patch clamp technique to primary cultures of rat osteoblasts. In 0-Mg(2+) saline, 25% of cells showed a slowly developing inward current in response to bath perfusion with 1 mM or 100 microM NMDA. Antibodies against NMDA receptors stained approximately 26% of cells. When NMDA was applied by rapid superfusion, kinetics of the currents were similar to those of neuronal NMDA currents, reaching a peak within 20-30 ms. 1 mM Mg(2+) reduced current amplitude at negative holdi...Continue Reading
Citations
NMDA enhances stretching-induced differentiation of osteoblasts through the ERK1/2 signaling pathway
Related Concepts
Related Feeds
Anti-N-Methyl-D-Aspartate Receptor Encephalitis
Anti-N-Methyl-D-Aspartate (NMDA) receptor encephalitis is a form of of brain inflammation due to antibodies against NMDA receptors. Discover the latest research on anti-NMDA receptor encephalitis here.