Neuroprotective Effects of Magnesium on Metabolic Disturbance in Fetal Hippocampal Slices After Oxygen-Glucose Deprivation: Mediation By Nitric Oxide System

Abstract

Objective: We investigated the effects of magnesium on metabolic disturbances in hippocampal slices prepared from fetal guinea pigs after oxygen-glucose deprivation (OGD).

Methods: Metabolic disturbances were assessed by measuring changes in energy metabolism and protein synthesis. In addition we determined cyclic guanosine monophosphate (cGMP) concentrations in the slices after OGD, as a measure of nitric oxide (NO) production, to clarify whether a possible neuprotective effect of magnesium is mediated in part through the NO system.

Results: Twelve hours after oxygen-glucose deprivation, adenosine triphosphate (ATP) concentration and protein synthesis in the hippocampal slices were significantly reduced depending on the severity of OGD. A higher magnesium concentration in the incubation medium from 1.3 mM to 3.9 mM 2 hours before OGD significantly improved the recovery of ATP and protein synthesis, whereas treatment after OGD was ineffective. The cGMP concentrations increased dramatically in hippocampal slices 10 minutes after OGD, indicating a significant increase in NO production. When the concentration of magnesium in the artificial cerebrospinal fluid was increased 2 hours before OGD the rise in tissue levels of cGMP was considerably reduced. Again, treatment after OGD had no effect.

Conclusion: We conclude that increasing magnesium concentration in the artificial cerebrospinal fluid before OGD alleviated metabolic disturbances in hippocampal slices from mature fetal guinea pigs, whereas treatment after OGD had no effect. This neuroprotective property of magnesium might be mediated in part through the inhibition of NO production shortly after OGD.

Keywords

Energy metabolism fetal brain ischemia nitric oxide protein synthesis

Get full access to this article

View all access options for this article.

References

1. Volpe JJ . Neurology of the newborn. 5th ed. Philadelphia: Saunders, 1995.

2. Berger R , Garnier Y . Pathophysiology of perinatal brain damage. Brain Res Rev 1999;30:107-134.

3. McDonald JW , Johnston MV . Physiological and pathophysiological roles of excitatory amino acids during central nervous system development. Brain Res Rev 1990;15:41-70.

4. Nelson KB , Grether JK . Can magnesium sulfate reduce risk of cerebral palsy in very low birthweight infants? Pediatrics 1995;95:263-269.

5. Schendel DE , Berg CJ , Ycargin-Allsopp M , Boyle CA , Decougle P . Prenatal magnesium sulfate exposure and the risk of cerebral palsy or mental retardation among very low-birth-weight children aged 3 to 5 years. JAMA 1996;276:1805-1810.

6. Grether JK , Hoogstrate J , Walsh-Greene E , Nelson KB . Magnesium sulfate for tocolysis and risk of spastic cerebral palsy in premature children born to women without preeclampsia. Am J Obstet Gynecol 2000;18:717-725.

7. Altura BM , Altura BT . Magnesium ions and contraction of vascular smooth muscles: Relationship to some vascular diseases. Fed Proc 1981;40:2672-2679.

8. Choi D . The role of glutamate neurotoxicity in hypoxic-ischemic neuronal death. Annu Rev Neurosci 1990;13:171-182.

9. Hallak M , Hotra JW , Kupsky WJ . Magnesium sulfate protection of fetal rat brain from severe maternal hypoxia. Obstet Gynecol 2000;96:124-128.

10.

10. Hoffman DJ , Marro PJ , McGowan JE , Mishra OP , Delivoria-Papadopoulos M . Protective effect of MgSO4 infusion on NMDA receptor binding characteristics during cerebral cortical hypoxia in the newborn piglet. Brain Res 1994;644:144-149.

11.

11. Maulik D , Zanelli S , Numagami Y , Ohnishi ST , Mishra OP , Delivoria-Papadopoulos M . Oxygen free radical generation during in-utero hypoxia in the fetal guinea pig brain: The effects of maturity and of magnesium sulfate administration. Brain Res 1999;817:117-122.

12.

12. Mishra OP , Delivoria-Papadopoulos M . NMDA receptor modification in the fetal guinea pig brain during hypoxia. Neurochemical Res 1992;17:1211-1216.

13.

13. Nowak L , Bergestovski P , Ascher P , Herbelt A , Prochiantz A . Magnesium gates glutamate activated channels in mouse central neurons. Nature 1984;307:462-465.

14.

14. Sameshima H , Ota A , Ikenoue T . Pretreatment with magnesium sulfate protects against hypoxic-ischemic brain injury but post-asphyxial treatment worsens brain damage in seven-day-old rats. Am J Obstet Gynecol 1999;180:725-730.

15.

15. Thordstein M , Bagenholm R , Thiringer K , Kjellmer I . Scavengers of free oxygen radicals in combination with magnesium ameliorate perinatal hypoxic-ischemic brain damage in the rat. Pediatr Res 1993;34:23-26.

16.

16. De Haan HH , Gunn AJ , Williams CE , Heymann MA , Gluckman PD . Magnesium sulfate during asphyxia in near-term fetal lambs does not compromise the fetus but does not reduce cerebral injury. Am J Obstet Gynecol 1997;176:18-27.

17.

17. Greenwood K , Cox P , Mehmet H , et al. Magnesium sulfate treatment after transient hypoxia-ischemia in the newborn piglet does not protect against cerebral damage. Pediatr Res 2000;48:346-350.

18.

18. Beckman JS , Chen J , Ischiropoulos H , Conger KA . Inhibition of nitric oxide synthesis and cerebral protection. In: Krieglstein J , Oberpichler-Schwenk H , eds. Pharmacology of cerebral ischemia. Stuttgart: Wissenschaftliche Verlasggesellschaft mbH, 1992:383-394.

19.

19. Berger R , Jensen A , Paschen W . Metabolic disturbances in hippocampal slices of fetal guinea pigs during and after oxygen-glucose deprivation: Is nitric oxide involved? Neurosci Lett 1998;245:163-166.

20.

20. Paschen W . Comparison of biochemical disturbances in hippocampal slices of gerbil and rat during and after in vitro ischemia. Neurosci Lett 1995;199:41-44.

21.

21. Berger R , Djuricic B , Jensen A , Hossmann KA , Paschen W . Ontogenetic differences in energy metabolism and inhibition of protein synthesis in hippocampal slices during in vitro ischemia and 24 h of recovery. Dev Brain Res 1996;91:281-291.

22.

22. Djuricic B , Berger R , Paschen W . Protein synthesis and energy metabolism in hippocampal slices during extended (24 hours) recovery following different periods of ischemia. Metab Brain Dis 1994;9:377-389.

23.

23. Atkinson DE . The energy charge of the adenylate pool as a regulatory parameter: Interaction with feedback modifiers. Biochemistry 1968;7:4030-4034.

24.

24. Lowry OH , Rosenbrough NJ , Farr AL , Randall R . Protein measurement with the folin phenol reagent. J Biol Chem 1951;193:265-275.

25.

25. Smith CB , Deibler GE , Eng N , Schmidt K , Sokoloff L . Measurement of local cerebral protein synthesis in vivo: Influence of recycling of amino acids derived from protein degradation. Proc Natl Acad Sci U S A 1988;85:9341-9345.

26.

26. Lipsitz PJ . The clinical and biochemical effects of excess magnesium in the newborn. Pediatrics 1971;47:501-509.

27.

27. Mittendorf R , Covert R , Boman J , Khoshnood B , Lee KS , Siegler M . Is tocolytic magnesium sulphate associated with increased total paediatric mortality? Lancet 1997;350:1517-1518.

28.

28. Cruikshank DP , Pitkin RM , Reynolds WA , Williams GA , Hargis GK . Effects of magnesium sulfate treatment on perinatal calcium metabolism. I. Maternal and fetal responses. Am J Obstet Gynecol 1979;134:243-249.

29.

29. Green KW , Key TC , Coen R , Resnik R . The effects of maternally administered magnesium sulfate on the neonate. Am J Obstet Gynecol 1983;146:29-33.

30.

30. Hallak M , Cotton DB . Transfer of maternally administered MgSO4 into the fetal compartment of the rat: Assessment of amniotic fluid, blood, and brain concentrations. Am J Obstet Gynecol 1993;169:427-431.

31.

31. Ringel M , Bryan RM , Vannucci RC . Regional cerebral blood flow during hypoxia-ischemia in the immature rat: Comparison of iodoantipyrine and iodoamphetamine as radioactive tracers. Dev Brain Res 1991;59:231-235.

32.

32. Vannucci RC , Lyons DT , Vasta F . Regional cerebral blood flow during hypoxia-ischemia in immature rats. Stroke 1998;19:245-250.

33.

33. Hossmann KA , Widmann R , Wiessner C , Dux E , Djuricic B , Röhn G . Protein synthesis after global ischemia and selective vulnerability. In: Krieglstein J , Oberpichler-Schwenk H , eds. Pharmacology of cerebral ischemia. Stuttgart: Wissenschaftliche Verlagsgesellschaft mbH, 1992:289-299.

34.

34. Hossmann KA . Disturbances of cerebral protein synthesis and ischemic cell death. Prog Brain Res 1993;96:161-177.

35.

35. Hossmann KA . Ischemia-mediated neuronal injury. Resuscitation 1993;26:225-235.

36.

36. Kleihues P , Hossmann KA , Pegg AE , Kobayashi K , Zimmermann V . Resuscitation of the monkey brain after one hour of complete ischemia. III. Indications of metabolic recovery. Brain Res 1975;95:61-73.

37.

37. Bodsch W , Takahashi K , Barbier A , Ophoff BG , Hossmann KA . Cerebral protein synthesis and ischemia. Prog Brain Res 1985;63:197-210.

38.

38. Thilmann R , Xie Y , Kleihues P , Kiessling M . Persistent inhibition of protein synthesis precedes delayed neuronal cell death in postischemic gerbil hippocampus. Acta Neuropathol 1986;71:88-93.

39.

39. Goto K , Ishige A , Sekiguchi K , et al. Effects of cycloheximide on delayed neuronal death in rat hippocampus. Brain Res 1990;534:299-302.

40.

40. Dragunow M , Beilharz E , Sirimanne E , et al. Immediate-early gene protein expression in neurons undergoing delayed death, but not necrosis, following hypoxic-ischemic injury to the young rat brain. Mol Brain Res 1994;25:19-33.

41.

41. Li Y , Chopp M , Zhang ZG , Zaloga C . Induction of DNA fragmentation after 10 to 120 minutes of focal cerebral ischemia in rats. Stroke 1995;26:1252-1258.

42.

42. Mehmet H , Yue X , Squier MV , et al. Increased apoptosis in the cingulate sulcus of newborn piglets following transient hypoxia-ischemia is related to the degree of high energy phosphate depletion during the insult. Neurosci Lett 1994;181:121-125.

43.

43. Hamada Y , Hayakawa T , Hattori H , Mikawa H . Inhibitor of nitric oxide synthesis reduces hypoxic-ischemic brain damage in the neonatal rat. Pediatr Res 1994;35:10-14.

44.

44. Ferriero DM , Holtzman DM , Black SM , Sheldon RA . Neonatal mice lacking neuronal nitric oxide synthase are less vulnerable to hypoxic-ischemic injury. Neurobiol Dis 1996;3:64-71.

45.

45. American College of Obstetricians and Gynecologists . Hypertension in pregnancy, ACOG technical bulletin no. 219. Washington DC: American College of Obstetricians and Gynecologists, 1996.

46.

46. Hossmann KA . Mechanisms of ischemic injury: Is glutamate involved? In: Krieglstein J , Oberpichler-Schwenk H , eds. Pharmacology of cerebral ischemia. Stuttgart: Wissenschaftliche Verlagsgesellschaft GmbH, 1994:239-251.

47.

47. Marks KA , Mallard CE , Roberts I , Williams CE , Gluckman PD , Edwards AD . Nitric oxide synthase inhibition attenuates delayed vasodilation and increases injury after cerebral ischemia in fetal sheep. Pediatr Res 1996;40:185-191.

48.

48. Marks KA , Mallard CE , Roberts I , Williams CE , Gluckman PD , Edward AD . Nitric oxide synthase inhibition and delayed cerebral injury after severe cerebral ischemia in fetal sheep. Pediatr Res 1999;46:8-13.

49.

49. Seelig JM , Wei EP , Kontos HA , Choi SC , Becker DP . Effect of changes in magnesium ion concentration on cat cerebral arterioles. Am J Physiol 1983;245:H22-H26.