The Changes in Serum and Cerebrospinal Fluid Ca2+, Mg2+, and Ca2+/Mg2+ Ratio in Neuropathic Rats
Year: 2004
Type: article
Abstract: Background: Central sensitization of neuropathic pain is associated with an influx of extracellular calcium via the opening of N-methyl-D-aspartate (NMDA) receptor-gated ion channels, which is usually blocked by a magnesium plug.Many studies have found that intrathecal or intraperitoneal magnesium suppress neuropathic pain.Therefore, it is possible that serum and cerebrospinal fluid Ca 2+ , Mg 2+ , and Ca 2+ /Mg 2+ ratio are changed in neuropathic pain.The purpose of this study was evaluated changes in serum and cerebrospinal fluid Ca 2+ , Mg 2+ , and Ca 2+ /Mg 2+ ratio in neuropathic rats.Methods: Male Sprague-Dawley rats were prepared with tight ligation of the left lumbar 5th and 6th spinal nerves to produce neuropathic pain.The threshold of mechanical allodynia was evaluated by the up-down method using withdrawal response to a von Frey filaments stimulus on the 3rd, 7th, and 14th day.Rats with a threshold of less than 4 gram were selected as the experimental group.On the 16th day, serum and cerebrospinal fluid Ca 2+ , Mg 2+ , and Ca 2+ /Mg 2+ ratio were measured.Experimental group data were then compared with those of an unoperated control group and an unligated sham group; each group contained 10 animals.Results: No statistic differences were found between groups.Conclusions: Our results suggest that serum and cerebrospinal fluid Ca 2+ , Mg 2+ , and Ca 2+ /Mg 2+ ratio in neuropathic rats do not differ from those of normal rats because of physiologic homeostasis is maintained by active transport through the blood-brain-barrier despite of activation of NMDA receptor-gated ion channels.However, we believe that the Mg 2+ ion-dependent voltage-gating in rats with neuropathic pain may be deficient in a chronic condition due to a decreased Mg 2+ binding affinity of the NMDA receptor-gated channel, as has been found in hippocampal granule cells in epileptic rats.(Korean J Anesthesiol 2004; 47: 580∼4) ꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏ
Source: Korean Journal of Anesthesiology
Authors: Sung Moon Jeong, Chul Ho Park, Jin Woo Shin, Jeong Gil Lim, Chung Lee, Sung Min Han
Institutions: Asan Medical Center, University of Ulsan
Language: English
Subfield: Physiology
Field: Medicine
Domain: Health Sciences
Open Access status: diamond
OpenAlex ID: W2320513821