CJA
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
This Article
Right arrow Full Text (PDF)
Right arrow Submit a scholarly reply
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Orser, B.
Right arrow Articles by Gelb, A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Orser, B.
Right arrow Articles by Gelb, A.

Canadian Journal of Anesthesia, Vol 44, 883-890, Copyright © 1997 by Canadian Anesthesiologists' Society

ARTICLES

Magnesium deficiency increases ketamine sensitivity in rats

B Orser, D Smith, S Henderson and A Gelb
Department of Anaesthesia, Sunnybrook Health Science Centre, University of Toronto. beverley.orscr@utoronto.ca

PURPOSE: Inhibition of the NMDA receptor likely contributes to ketamine's neurodepressive properties. Magnesium also inhibits the NMDA receptor by binding to a site associated with the ketamine-binding domain. Electrophysiological studies suggest that magnesium prevents ketamine from binding to the NMDA receptor and thereby prevents ketamine inhibition. We undertook an in vivo study to determine if magnesium deficiency was associated with an increased sensitivity to ketamine. METHODS: Weanling rats were maintained on a Mg(2+)-deficient or control diet for 14 days. In Study I, rats were anaesthetized then sacrificed and the Mg2+ concentrations in the brain and plasma were measured. In a second prospective study, experimental animals were rendered hypomagnesaemic and the potency of 125 mg.kg-1 ip ketamine was evaluated. Animals were then were fed a Mg(2+)-containing diet and ketamine sensitivity was re-examined 14 days later. RESULTS: The Mg(2+)-deficient diets rendered the rats hypomagnesaemic as indicated by the brain and plasma concentration of Mg2+. In Study 2, the time to loss of righting reflex was shorter; 1.9 +/- 0.3 min (n = 12) and 2.6 +/- 0.2 min (n = 16, P < 0.05), whereas the latency to toe pinch was prolonged: 25.0 +/- 5.8 min (n = 12) vs 3.1 +/- 2.1 min (n = 16, P < 0.05) in the Mg(2+)-deficient compared with age-matched control animals, respectively. The hypomagnesaemic animals had a higher death rate following ketamine injection. The increased sensitivity to ketamine was no longer apparent when the animals were re-tested following replenishment of Mg2+. CONCLUSION: Hypomagnesaemia is associated with an increased sensitivity to ketamine.


This article has been cited by other articles:


Home page
 Canadian J. AnesthesiaHome page
L. Dube and J.-C. Granry
The therapeutic use of magnesium in anesthesiology, intensive care and emergency medicine: a review: [L'usage therapeutique du magnesium en anesthesiologie, reanimation et medecine d'urgence]
Can J Anesth, August 1, 2003; 50(7): 732 - 746.
[Abstract] [Full Text] [PDF]

Home page
 Anesth. Analg.Home page
H.-T. Liu, M. W. Hollmann, W.-H. Liu, C. W. Hoenemann, and M. E. Durieux
Modulation of NMDA Receptor Function by Ketamine and Magnesium: Part I
Anesth. Analg., May 1, 2001; 92(5): 1173 - 1181.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1997 by the Canadian Anesthesiologists' Society.