Involvement of intracellular calcium on the phosphorylation of spinal N-methyl-D-aspartate receptor following electroacupuncture stimulation in rats.
This study examined the role of the intracellular calcium chelator, bis-(2-aminophenoxy)-ethane-N,N,N',N'-tetraacetic acid (BAPTA), in modulating the phosphorylation of the spinal N-methyl-d-aspartate receptor (NMDAR) NR1 and NR2B subunits after 2Hz electroacupuncture (EA) in rats. The level of EA analgesia was reduced by an intraperitoneal injection of BAPTA at a higher dose after terminating EA stimulation. At 60min after the EA treatment, the total number of c-fos-immunolabeled neurons in each region of the dorsal horn in lumbar segments (L4-5) was decreased by the BAPTA injection, particularly in the Nucleus proprius. The BAPTA injection decreased significantly the mean integrated optical density of phosphorylated NR1 subunit in the superficial laminae and neck region, and the phosphorylated NR2B subunit in the superficial laminae. Western blot analyses confirmed decreased levels of both phosphorylated subunits. In conclusion, intracellular calcium may play an important role in low-frequency EA analgesia by modulating the phosphorylation state of the spinal NMDAR subunits.
Jung
Taek Geun
TG
Department of Rehabilitation, College of Oriental Medicine, Dong-eui University, Busan 614-052, Republic of Korea.
Lee
Jun Hyuk
JH
Lee
In Seon
IS
Choi
Byung Tae
BT
D015667:Acupuncture Analgesia; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002614:Chelating Agents / Q000494:pharmacology; D015536:Down-Regulation; D004533:Egtazic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D015671:Electroacupuncture; D008161:Lumbosacral Region; D010146:Pain / Q000378:metabolism; D059408:Pain Management; D010766:Phosphorylation; D020671:Posterior Horn Cells / Q000378:metabolism*; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism*; D051381:Rats; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism*
D002614:Chelating Agents; C409466:NR1 NMDA receptor; C121001:NR2B NMDA receptor; D016760:Proto-Oncogene Proteins c-fos; D016194:Receptors, N-Methyl-D-Aspartate; D004533:Egtazic Acid; C025603:1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid; D002118:Calcium