This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a colleague Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (5) Citing Articles via Google Scholar Google Scholar Articles by Sakai, F. Articles by Amaha, K. Search for Related Content PubMed PubMed Citation Articles by Sakai, F. Articles by Amaha, K.

---

GENERAL ARTICLES

The Effects of Hypothermia on a Cloned Human Brain Glutamate Transporter (hGLT-1) Expressed in Chinese Hamster Ovary Cells: -[3H]L-Glutamate Uptake Study

Department of Anesthesiology and Critical Care Medicine, Tokyo Medical and Dental University, Tokyo, Japan

Address correspondence and reprint requests to Fumio Sakai, MD, PhD, Department of Anesthesiology and Critical Care Medicine, Tokyo Medical and Dental University, 5-45, Yushima 1-chome, Bunkyo-ku, Tokyo, 113-8519 Japan.

Hypothermia provides neuroprotection that inhibits increases in extracellular glutamate concentration during ischemia; however, the effect of hypothermia on the glutamate transporter is uncertain. A human glial glutamate transporter (hGLT-1) cDNA, isolated by screening a cDNA, library was cloned and stably transfected into Chinese hamster ovary cells. We assessed the effects of temperature on transporter activity in [³H]L-glutamate flux experiments at 23, 32, and 37°C. Hypothermia of 23°C and 32°C decreased [³H]L-glutamate uptake at 60 min, to 76.7% ± 7.3% (P < 0.05, n = 5) and 70.7% ± 7.5% (P < 0.05, n = 5) of uptake at 37°C, respectively. Reversed uptake of preloaded [³H]L-glutamate via hGLT-1 was not observed at any temperature. The specific uptakes (Q₁₀ values) for 37°C to 32°C and 32°C to 23°C at 30 min were 3.48 and 2.37, whereas they were 2.17 and 0.91, respectively, for 60 min. These changes suggest that hypothermia attenuates uptake of extracellular glutamate via hGLT-1 in a temperature- and time-dependent manner.

Implications: Under certain pathologic conditions, including cerebral ischemia and traumatic brain injury, glutamate neurotoxicity may initially be propagated by hypothermia due to relative failure of glutamate uptake via Human Glial Glutamate Transporter before a subsequent recovery of uptake.

This article has been cited by other articles:

				K. Okuyama, T. Matsukawa, M. Ozaki, D. I. Sessler, T. Nishiyama, M. Imamura, and T. Kumazawa Doxapram Produces a Dose-Dependent Reduction in the Shivering Threshold in Rabbits Anesth. Analg., September 1, 2003; 97(3): 759 - 762. [Abstract] [Full Text] [PDF]

				A. G. Doufas, A. Wadhwa, C.-M. Lin, Y. M. Shah, K. Hanni, and D. I. Sessler Neither Arm nor Face Warming Reduces the Shivering Threshold in Unanesthetized Humans Stroke, July 1, 2003; 34(7): 1736 - 1740. [Abstract] [Full Text] [PDF]