[Changes in Ca2+ concentration mediated by N-methyl-D-aspartate receptor in PO/AH neurons of anoxic SD rats].
OBJECTIVE
To study the changes of Ca2+ concentration mediated by N-methyl-D-aspartate (NMDA) receptor in the neurons in the preoptic area/anterior hypothalamus (PO/AH) of anoxic SD rats by investigating the properties of NMDA receptor.


METHODS
The effects of NMDA receptor agonist NMDA and antagonist vaproic acid (VPA) on the [Ca2+]i in PO/AH neurons were observed in SD rats with anoxia.


RESULTS
Under normal condition, the fluorescencet ratio was 0.95, which increased obviously in response to treatment with NMDA at 40 s and reached the peak value, 2.054, after 25 s with an increment of (109+/-52) %. After the addition of the agonist, the peak value reached 3.783 in 30 s and maintained the high level. The concentration of Ca2+ increased by (286+/-91) % after the treatment with NMDA. While in the anoxia group, the concentration of Ca2+ decreased by (103+/-45)% after the addition of VPA.


CONCLUSIONS
The increase in the concentration of Ca2+ results predominantly from the opening of NMDA receptor channel which allows Ca2+ influx. VPA may decrease the activity of NMDA receptor to reduce the Ca2+ concentration for the protection of the neurons against anoxia.
Zhao
Qing-ping
QP
Department of Neurosurgery, Zhujiang Hospital, First Military Medical University, Guangzhou 510282, China.
Zou
Fei
F
Chen
Guang-zhong
GZ
Li
Tie-lin
TL
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D005260:Female; D000860:Hypoxia / Q000378:metabolism*; D008297:Male; D009474:Neurons / Q000378:metabolism*; D011301:Preoptic Area / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D016194:Receptors, N-Methyl-D-Aspartate / Q000819:agonists / Q000502:physiology*; D014635:Valproic Acid / Q000494:pharmacology
D016194:Receptors, N-Methyl-D-Aspartate; D014635:Valproic Acid; D000255:Adenosine Triphosphate; D002118:Calcium