Does Mg2+ deficiency induce a long-term sensitization of the central nociceptive pathways?
In rats, a Mg(2+)-deficient diet, which in a few days dramatically decreased the Mg(2+) concentration in plasma, cerebrospinal fluid (CSF) and spinal cord, was accompanied by a significant lowering of the nociceptive threshold. After reloading, the Mg(2+) concentration was rapidly normalized in both spinal cord and CSF. In parallel, the neurological disturbances induced by Mg(2+) deficiency vanished in less that 24 h, but the reversal of the hyperalgesia was delayed for up to 11 to 20 days. In this model, repeated doses of dizocilpine (MK-801), a non-competitive NMDA receptor antagonist, given at start of the Mg(2+)-depleted diet, prevented hyperalgesia, suggesting the involvement of NMDA receptor channels. The delayed recovery of a normal pain threshold argues for long-term sensitization of the nociceptive pathways.
Alloui
Abdelkrim
A
INSERM EMI 9904/UdA Laboratoire Pharmacologie Fondamentale et Clinique de la Douleur, Faculté de Médecine, B.P. 38, 63001 Clermont-Ferrand, Cedex 1, France. abdelkrim.alloui@u-clermont1.fr
Begon
Sophie
S
Chassaing
Claude
C
Eschalier
Alain
A
Gueux
Eliette
E
Rayssiguier
Yves
Y
Dubray
Claude
C
D000818:Animals; D018691:Excitatory Amino Acid Antagonists / Q000378:metabolism / Q000494:pharmacology; D008274:Magnesium / Q000378:metabolism; D008275:Magnesium Deficiency / Q000139:chemically induced / Q000378:metabolism*; D010147:Pain Measurement / Q000187:drug effects / Q000379:methods*; D051381:Rats; D017208:Rats, Wistar; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D013995:Time
D018691:Excitatory Amino Acid Antagonists; D016194:Receptors, N-Methyl-D-Aspartate; D008274:Magnesium