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Original Article

Exp Neurobiol 2015; 24(1): 24-30

Published online March 31, 2015

https://doi.org/10.5607/en.2015.24.1.24

© The Korean Society for Brain and Neural Sciences

Intracerebroventricular Kainic Acid-Induced Damage AḀects Blood Glucose Level in d-glucose-fed Mouse Model

Chea-Ha Kim1 and Jae-Seung Hong2*

1Department of Pharmacology, Institute of Natural Medicine, College of Medicine, 2Department of Physical Education, College of Natural Science, Hallym University, Chuncheon 200-702, Korea

Correspondence to: *To whom correspondence should be addressed.
TEL: 82-33-248-2255, FAX: 82-33-254-0916
e-mail: jayshong@hallym.ac.kr

Received: February 6, 2015; Revised: February 23, 2015; Accepted: February 23, 2015

We have previously reported that the intracerebroventricular (i.c.v.) administration of kainic acid (KA) results in significant neuronal damage on the hippocampal CA3 region. In this study, we examined possible changes in the blood glucose level after i.c.v. pretreatment with KA. The blood glucose level was elevated at 30 min, began to decrease at 60 min and returned to normal at 120 min after D-glucose-feeding. We found that the blood glucose level in the KA-pretreated group was higher than in the saline-pretreated group. The up-regulation of the blood glucose level in the KA-pretreated group was still present even after 1~4 weeks. The plasma corticosterone and insulin levels were slightly higher in the KA-treated group. Corticosterone levels decreased whereas insulin levels were elevated when mice were fed with D-glucose. The i.c.v. pretreatment with KA for 24 hr caused a significant reversal of D-glucose-induced down-regulation of corticosterone level. However, the insulin level was enhanced in the KA-pretreated group compared to the vehicle-treated group when mice were fed with D-glucose. These results suggest that KA-induced alterations of the blood glucose level are related to cell death in the CA3 region whereas the up-regulation of blood glucose level in the KA-pretreated group appears to be due to a reversal of D-glucose feeding-induced down-regulation of corticosterone level.

Keywords: kainic acid, neuronal cell death, blood glucose, D-glucose-fed model

Kainic acid (KA) is an excitotoxin in a variety of brain regions, especially in the hippocampus, where it has been repeatedly observed to induce the loss of neurons [1]. KA-induced seizures in rats result in delayed neuronal necrosis in the hippocampus and limbic cortex [2]. Delayed neuronal losses were also reported in the rat hippocampal CA1 and CA3 regions following intraperitoneal (i.p.) [3] or intracerebroventricular (i.c.v.) administration of KA [4, 5]. KA, administered i.c.v. to mice, also induces significant lesion of CA3 pyramidal neurons [6, 7, 8, 9, 10, 11]. It is generally agreed that KA-induced hyperexcitability and subsequent neuronal damage is converged on the hippocampal formation.

Several lines of evidence have demonstrated that seizure elevates cerebral metabolic rates [12] and glycolysis [13], which may lead to the accumulation of metabolic intermediates such as lactate and adenosine. In addition, Uysal et al. [14], reported that insulin reduces KA-induced seizure activity. Furthermore, Koenig and Cho [15] showed that hypothalamic KA receptor mRNA levels are elevated in insulin-induced hypoglycemic rats, suggesting that KA receptor expression may be dynamically regulated depending on the level of blood glucose. We have recently found that the acute supraspinal administration of KA produces a hyperglycemia effect. This finding suggests that the up-regulation of blood glucose level during the activation of central kainite receptors may be associated with hippocampal neuronal cell death, especially in the CA3 region. However, possible changes in the regulation of blood glucose level after damage to the hippocampal cells by KA have not been characterized yet. Thus, in the present study, we intended to investigate the blood glucose level changes induced by i.c.v. administered KA in a D-glucose-fed animal model. Twenty-four hours after the i.c.v. treatment with KA or saline, mice were fed with D-glucose and the blood glucose level was determined. Furthermore, changes in plasma corticosterone and insulin levels in saline- and KA-pretreated groups were evaluated.

These experiments were approved by the Hallym University Animal Care and Use Committee (Registration Number: Hallym 2009-05-01). All procedures were conducted in accordance with the 'Guide for Care and Use of Laboratory Animals' published by the National Institutes of Health.

Experimental animals

Male ICR mice (MJ Co., Seoul, Korea) weighing 20~25 g were used for all experiments. Animals were housed 5 per cage in a room maintained at 22±0.5℃ with an alternating 12 h light-dark cycle. Food and water were available ad libitum. The animals were allowed to adapt to the laboratory for at least 2 h before testing and each mouse was only used once. Experiments were performed during the light phase of the cycle (10:00~17:00).

Intracerebroventricular (i.c.v) injection

I.c.v. administration was performed according to Haley TJ's [16] method. Each mouse was grasped firmly without anesthesia by the loose skin behind the head. The skin was pulled taut. A 30-gauge needle attached to a 25 µl syringe was inserted perpendicularly through the bregma of the skull into the brain with the depth of 2.4 mm and solution was injected. The injection site was 2 mm from either side of the midline. The i.c.v. injection volumes were 5 µl, and the injection sites were verified by injecting a similar volume of 1% methylene blue solution and determining the distribution of the injected dye in the ventricular space. The experiments were performed only when the success rate of i.c.v injection was over 95%.

Measurement of blood glucose level

The blood glucose level was measured at 30, 60 and 120 min after the D-glucose administration. As much blood as possible was collected from the tail vein with a minimum volume of 1 µl. The glucose level was measured using Accu-Chek Performa blood glucose monitoring system (glucometer) (Mannheim, Baden-Württemberg, Germany).

Corticosterone assay and blood sampling

The plasma corticosterone level was determined using the fluorometric determination method [17]. Four hundred microliters of blood were collected by puncturing the retro-orbital venous plexus. Plasma was separated by centrifugation and stored at -80℃ until assayed.

Insulin ELISA assay

In Mouse Insulin ELISA, biotin conjugated anti insulin, along with a standard or the sample, is incubated in monoclonal anti-insulin-coated wells to capture insulin bound with biotin conjugated anti insulin. After 2 h incubation and washing, HRP (horse radish peroxidase) conjugated streptavidin is added, followed by another 30 min of incubation. After washing, HRP conjugated streptavidin remaining in wells is reacted with a substrate chromogen reagent (TMB) for 20 min. The reaction is stopped by addition of an acidic solution and the absorbance of the yellow product is measured spectrophotometrically at 450 nm. The absorbance is proportional to the insulin concentration. The standard curve is prepared by plotting absorbance against standard insulin concentrations. Insulin concentrations in unknown samples are then determined using this standard curve.

In Mouse Insulin ELISA, biotin conjugated anti insulin, along with a standard or the sample, is incubated in monoclonal anti-insulin-coated wells. Afterwards, horse radish peroxidase (HRP) conjugated streptavidin remaining in the wells is reacted with a substrate chromogen reagents and the reaction is stopped by addition of an acidic solution. Absorbance is then measured spectrophotometrically at 450 nm.

Drugs

Kainic acid and D-glucose were purchased from Sigma chemical Co. (St. Louis, MO, USA). D-glucose was dissolved in sterile saline (0.9070 NaCl solution) and kainic acid was prepared in phosphate-buffered saline (PBS) as the vehicle.

Statistical analysis

Statistical analysis was carried out by the student t test using GraphPad Prism Version 4.0 for Windows (GraphPad Software, San Diego, CA, USA). P-values less than 0.05 were considered to indicate statistical significance. All values were expressed as the mean±S.E.M. In our study, we established the mean blood glucose value of the control group through several experiments under matching conditions. Selected mice with the established blood glucose levels were then used in replication experiments.

Effects of i.c.v. pretreatment with KA on the blood glucose level in D-glucose-fed mice model

After i.c.v. pretreatment with KA (from 0.01 to 0.1 µg) for 24 h, mice were fed orally with D-glucose (2 g/kg). The blood glucose level was measured at 30, 60 and 120 min after D-glucose feeding. As shown in Fig. 1A, the blood glucose was elevated at 30min and returned to base line after 2 hours. This level was maintained up to 2 h after D-glucose feeding in the control group. KA pretreated i.c.v. for 24 h caused an up-regulation of the blood glucose level in a dose-dependent manner.

Effects of various periods of i.c.v. pretreatment with KA on the blood glucose level in D-glucose-fed model

After i.c.v. pretreatment with KA (0.1 µg) for 1, 2, 3, or 4 weeks, mice were fed orally with D-glucose (2 g/kg). The blood glucose level was measured at 30 min after D-glucose feeding. As shown in Fig. 1B, the blood glucose level in the i.c.v. KA-pretreated group for weeks 1, 2, 3, and 4 was higher than that of the saline-pretreated group after the mice were orally fed with D-glucose.

Effects of i.c.v. pretreatment with KA on the plasma corticosterone and insulin levels in D-glucose-fed model

To determine whether the glucocorticoid and insulin systems are involved in the up-regulation of blood glucose level in the KA-pretreated group, the effect of i.c.v. pretreatment with KA (0.1 µg) on plasma corticosterone level in the D-glucose-fed group was investigated. The plasma corticosterone and insulin levels were measured before and 30 min after D-glucose feeding. As shown in Fig. 2, the plasma corticosterone and insulin levels were higher in the KA-treated group. When the mice were orally fed with D-glucose, the plasma corticosterone decreased slightly whereas the plasma insulin level was elevated. KA i.c.v. pretreatment for 24 hr caused a significant reversal of D-glucose-induced down-regulation of corticosterone level (Fig. 2A). However, the plasma insulin level was further enhanced in the KA-pretreated group compared to the vehicle-treated group when mice were fed with D-glucose as shown in Fig. 2B.

KA is a well-known excitatory, neurotoxic substance. In mice, morphological damage of the hippocampus induced by KA administered intracerebroventricularly (i.c.v) was markedly concentrated in the CA3 pyramidal neurons [10]. Several lines of evidence indicate that the activation of kainate receptors located in the hippocampal formation plays an important role in synaptic physiology and plasticity [18, 19]. Previously, KA-induced alterations of nocifensive behaviors were correlated with the neuronal death of the hippocampal formation, especially CA3 pyramidal neurons [20]. KA is a well-known potent agonist of the α-amino-3-hydroxy-5-methyl-4-isoxazoleproprionic acid (AMPA)/kainate class of glutamate receptors, which, when injected directly into the brain or systemically, induces a characteristic pattern of persistent seizure activity [21]. KA activates ionotropic glutamate receptors, and selectively induces cell death in postsynaptic neurons in the CA3 and CA1 hippocampal regions. This may be the possible mechanism through which KA causes brain damage and seizure [22, 23, 24, 25, 26].

It is well known that seizures result in altered glucose metabolism, the reduction of intracellular energy metabolites such as ATP, ADP and phosphocreatine as well as the accumulation of metabolic intermediates such as lactate and adenosine. In particular, it has been suggested that the duration and extent of glucose dysregulation may be a predictor of the pathological outcome of status. Although the direct effects of glycemic control on brain metabolism and the effects of managing systemic glucose concentrations in epilepsy have been characterized [27], the direct effect of KA on the blood glucose level is not yet well characterized. Previous studies have demonstrated that the hypoglycemic condition prevents neuronal cell death in stroke animal models whereas the hyperglycemia condition aggravates neuronal cell death in animal stroke models [28, 29]. Johansen and Diemer [30] demonstrated that blood glucose level may influence KA-induced neurotoxicity. They found that systemic injection of KA in hyperglycemic rats resulted in higher lethality as well as more severe hippocampal CA1 damage, whereas hypoglycemia protected against KA-induced hippocampal CA1 damage [30]. A recent study demonstrated that KA administration leads to hyperglycemia. This may cause CA3 damage. Administration of repaglinide, PTX (pertussis toxin), and sulfonylureas also had neuroprotective effects against KA induced CA3 damage [31, 32, 33].

In the present study, up-regulation of the blood glucose level in the D-glucose-fed group was more pronounced in the KA-pretreated group compared to the saline pretreated group. The up-regulation of blood glucose level in the D-glucose-fed mice model was maintained in the KA-pretreated group for up to 4 weeks. Taken together, the results from all of these studies, including the present study, suggest that neurodegeneration in the CA3 region of the hippocampus by KA is associated with up-regulation of the blood glucose level when mice are fed with D-glucose.

The present study revealed that i.c.v. pretreatment with KA for 24 hr elevates plasma corticosterone level and insulin level. This finding suggests that i.c.v. KA administration continues to activate the HPA axis 24 hr after KA administration. Our finding is partially in line with a previous report that an acute intrahippocampal injection of KA elevated plasma corticosterone level in rats [34], indicating that the glucocorticoid system is strongly activated when animals are injected with KA. In addition, D-glucose feeding causes the down-regulation of corticosterone and the up-regulation of insulin levels. This finding suggests that the down-regulation of plasma corticosterone and the up-regulation of insulin can, on the whole, lower blood glucose level after D-glucose ingestion. Additionally, the corticosterone level in the KA-pretreated group was higher than in the saline-treated group when mice were fed with D-glucose. This up-regulation of corticosterone might be responsible for the up-regulation of blood glucose in the KA-pretreated group after D-glucose feeding. Furthermore, D-glucose-induced up-regulation of insulin was further enhanced in the KA-pretreated group, suggesting that up-regulation of blood glucose in the KA-pretreated group may result in further enhancement of insulin level in the KA-pretreated group to maintain glucose homeostasis.

Some preclinical studies have reported that hyperglycemia is often observed in focal ischemia animal models [35, 36]. In addition, several lines of evidence have demonstrated that, in some clinical studies, hyperglycemia or abnormal glucose regulation is often observed in stroke patient groups. For example, Jia et al [37] reported that diabetic-like symptoms were observed in about 45% of ischemic stroke patients examined using an oral glucose tolerance test. In addition, Els et al. [38] reported that 58% of stroke patients showed diabetes mellitus-like symptoms up to 12 weeks after ischemic attack. Although it is too early to make an assumption at the present time, it can be speculated that the HPA axis might be in an activated state in stroke survivors. The neuronal damage in some areas of the brain may activate the HPA axis in these individuals. Thus, it might be necessary in future studies to check blood glucose and glucocorticoid hormone levels in post-stroke patients to determine whether the hyperglycemic state present in some patients is correlated with the up-regulated glucocorticoid system.

In conclusion, the present study demonstrates that supraspinal pretreatment with KA for 24 h causes an up-regulation of the blood glucose level in a D-glucose-fed mice model. The up-regulation of blood glucose in the KA-pretreated group appears to be due to the activation of the glucocorticoid system.

Fig. 1. Effect of i.c.v. pretreatment with KA on the blood glucose level in D-glucose-fed model. (A) After mice were pretreated i.c.v. with KA (from 0.01 to 0.1 µg) for 24 h, they were fed orally with D-glucose (2 g/kg). The blood glucose level was measured at 30, 60 and 120 min after D-glucose feeding. (B) After mice were pretreated i.c.v. with KA (0.1 µg) for 1, 2, 3, or 4 weeks, they were fed orally with D-glucose (2 g/kg). The blood glucose level was measured at 30 min after D-glucose feeding. The vertical bars indicate the standard error of mean (***p <0.001, **p <0.01, *p <0.05; compared to PBS+Saline, +++p <0.001, ++p <0.01, +p <0.05; compared to PBS+ D-glucose). The number of animals used for each group was 8~10.
Fig. 2. Effect of i.c.v. pretreatment with KA on the plasma corticosterone (A) and insulin levels (B) in D-glucose-fed model. After mice were pretreated i.c.v. with KA (0.1 µg) for 24 h, they were fed orally with D-glucose (2 g/kg). The plasma corticosterone and insulin levels were measured before and 30 min after D-glucose feeding. The vertical bars indicate the standard error of mean (***p <0.001, **p <0.01, *p <0.05; compared to PBS+Saline, +++p <0.001; compared to PBS+D-glucose). The number of animals used for each group was 8~10.
  1. Dong H, Csernansky CA, Chu Y, Csernansky JG. Intracerebroventricular kainic acid administration to neonatal rats alters interneuron development in the hippocampus. Brain Res Dev Brain Res 2003;145:81-92.
  2. Sperk G. Kainic acid seizures in the rat. Prog Neurobiol 1994;42:1-32.
    Pubmed
  3. Baik EJ, Kim EJ, Lee SH, Moon C. Cyclooxygenase-2 selective inhibitors aggravate kainic acid induced seizure and neuronal cell death in the hippocampus. Brain Res 1999;843:118-129.
    Pubmed
  4. Matsuoka Y, Okazaki M, Takata K, Kitamura Y, Ohta S, Sekino Y, Taniguchi T. Endogenous adenosine protects CA1 neurons from kainic acid-induced neuronal cell loss in the rat hippocampus. Eur J Neurosci 1999;11:3617-3625.
    Pubmed
  5. Roe DL, Bardgett ME, Csernansky CA, Csernansky JG. Induction of Fos protein by antipsychotic drugs in rat brain following kainic acid-induced limbic-cortical neuronal loss. Psychopharmacology (Berl) 1998;138:151-158.
    Pubmed
  6. Lee HK, Seo YJ, Choi SS, Kwon MS, Shim EJ, Lee JY, Suh HW. Role of gamma-aminobutyricacidB(GABA(B)) receptors in the regulation of kainic acid-induced cell death in mouse hippocampus. Exp Mol Med 2005;37:533-545.
    Pubmed
  7. Lee HK, Choi SS, Han EJ, Lee JY, Kwon MS, Shim EJ, Seo YJ, Suh HW. Role of nicotinic acetylcholine receptors in the regulation of kainic acid-induced hippocampal cell death in mice. Brain Res Bull 2004;64:309-317.
    Pubmed
  8. Lee HK, Choi SS, Han EJ, Han KJ, Suh HW. Role of glutamate receptors and an on-going protein synthesis in the regulation of phosphorylation of Ca2+/calmodulin-dependent protein kinase II in the CA3 hippocampal region in mice administered with kainic acid intracerebroventricularly. Neurosci Lett 2003;348:93-96.
    Pubmed
  9. Lee HK, Choi SS, Han KJ, Han EJ, Suh HW. Cycloheximide inhibits neurotoxic responses induced by kainic acid in mice. Brain Res Bull 2003;61:99-107.
    Pubmed
  10. Lee JK, Choi SS, Lee HK, Han KJ, Han EJ, Suh HW. Effects of MK-801 and CNQX on various neurotoxic responses induced by kainic acid in mice. Mol Cells 2002;14:339-347.
    Pubmed
  11. Ferraguti F, Corti C, Valerio E, Mion S, Xuereb J. Activated astrocytes in areas of kainate-induced neuronal injury upregulate the expression of the metabotropic glutamate receptors 2/3 and 5. Exp Brain Res 2001;137:1-11.
    Pubmed
  12. Fernandes MJ, Dubé C, Boyet S, Marescaux C, Nehlig A. Correlation between hypermetabolism and neuronal damage during status epilepticus induced by lithium and pilocarpine in immature and adult rats. J Cereb Blood Flow Metab 1999;19:195-209.
    Pubmed
  13. Fray AE, Boutelle M, Fillenz M. Extracellular glucose turnover in the striatum of unanaesthetized rats measured by quantitative microdialysis. J Physiol 1997;504:721-726.
    Pubmed
  14. Uysal H, Kuli P, Cağlar S, Inan LE, Akarsu ES, Palaoğlu O, Ayhan IH. Antiseizure activity of insulin: insulin inhibits pentylenetetrazole, penicillin and kainic acid-induced seizures in rats. Epilepsy Res 1996;25:185-190.
    Pubmed
  15. Koenig JI, Cho JY. Provocation of kainic acid receptor mRNA changes in the rat paraventricular nucleus by insulin-induced hypoglycaemia. J Neuroendocrinol 2005;17:111-118.
    Pubmed
  16. Haley TJ. Pharmacological effects produced by intracerebral administration of drugs of unrelated structure to conscious mice. Arch Int Pharmacodyn Ther 1957;110:239-244.
    Pubmed
  17. Glick D, Vonredlich D, Levine S. Fluorometric determination of corticosterone and cortisol in 0.02-0.05 milliliters of plasma or submilligram samples of adrenal tissue. Endocrinology 1964;74:653-655.
    Pubmed
  18. Schmitz D, Mellor J, Breustedt J, Nicoll RA. Presynaptic kainate receptors impart an associative property to hippocampal mossy fiber long-term potentiation. Nat Neurosci 2003;6:1058-1063.
    Pubmed
  19. Contractor A, Swanson G, Heinemann SF. Kainate receptors are involved in short- and long-term plasticity at mossy fiber synapses in the hippocampus. Neuron 2001;29:209-216.
    Pubmed
  20. Shim EJ, Seo YJ, Kwon MS, Ham YO, Choi OS, Lee JY, Choi SM, Suh HW. The intracerebroventricular kainic acid-induced damage affects animal nociceptive behavior. Brain Res Bull 2007;73:203-209.
    Pubmed
  21. Coyle JT. Neurotoxic action of kainic acid. J Neurochem 1983;41:1-11.
    Pubmed
  22. Kerwin R, Patel S, Meldrum B. Quantitative autoradiographic analysis of glutamate binding sites in the hippocampal formation in normal and schizophrenic brain post mortem. Neuroscience 1990;39:25-32.
    Pubmed
  23. Ben-Ari Y. Limbic seizure and brain damage produced by kainic acid: mechanisms and relevance to human temporal lobe epilepsy. Neuroscience 1985;14:375-403.
    Pubmed
  24. Nadler JV, Evenson DA. Use of excitatory amino acids to make axon-sparing lesions of hypothalamus. Methods Enzymol 1983;103:393-400.
    Pubmed
  25. Schwob JE, Fuller T, Price JL, Olney JW. Widespread patterns of neuronal damage following systemic or intracerebral injections of kainic acid: a histological study. Neuroscience 1980;5:991-1014.
    Pubmed
  26. Nadler JV, Perry BW, Cotman CW. Intraventricular kainic acid preferentially destroys hippocampal pyramidal cells. Nature 1978;271:676-677.
    Pubmed
  27. Schauwecker PE. The effects of glycemic control on seizures and seizure-induced excitotoxic cell death. BMC Neurosci 2012;13:94.
    Pubmed
  28. Tang Y, Lu A, Aronow BJ, Wagner KR, Sharp FR. Genomic responses of the brain to ischemic stroke, intracerebral haemorrhage, kainate seizures, hypoglycemia, and hypoxia. Eur J Neurosci 2002;15:1937-1952.
    Pubmed
  29. Kagansky N, Levy S, Knobler H. The role of hyperglycemia in acute stroke. Arch Neurol 2001;58:1209-1212.
    Pubmed
  30. Johansen FF, Diemer NH. Influence of the plasma glucose level on brain damage after systemic kainic acid injection in the rat. Acta Neuropathol 1986;71:46-54.
    Pubmed
  31. Kim CH, Park SH, Sim YB, Sharma N, Kim SS, Lim SM, Jung JS, Suh HW. Effect of pertussis and cholera toxins administered supraspinally on CA3 hippocampal neuronal cell death and the blood glucose level induced by kainic acid in mice. Neurosci Res 2014;89:31-36.
    Pubmed
  32. Kim CH, Park SH, Sim YB, Kim SS, Kim SJ, Lim SM, Jung JS, Suh HW. Effect of tolbutamide, glyburide and glipizide administered supraspinally on CA3 hippocampal neuronal cell death and hyperglycemia induced by kainic acid in mice. Brain Res 2014;1564:33-40.
    Pubmed
  33. Kim CH, Park SH, Sim YB, Kim SS, Kim SJ, Lim SM, Jung JS, Suh HW. Effects of nateglinide and repaglinide administered intracerebroventricularly on the CA3 hippocampal neuronal cell death and hyperglycemia induced by kainic acid in mice. Brain Res Bull 2014;104:36-41.
    Pubmed
  34. Daniels WM, Jaffer A, Engelbrecht AH, Russell VA, Taljaard JJ. The effect of intrahippocampal injection of kainic acid on corticosterone release in rats. Neurochem Res 1990;15:495-499.
    Pubmed
  35. Auer RN. Insulin, blood glucose levels, and ischemic brain damage. Neurology 1998;51:S39-S43.
    Pubmed
  36. Voll CL, Auer RN. The effect of postischemic blood glucose levels on ischemic brain damage in the rat. Ann Neurol 1988;24:638-646.
    Pubmed
  37. Jia Q, Zheng H, Zhao X, Wang C, Liu G, Wang Y, Liu L, Li H, Zhong L, Wang Y, Investigators for the Survey on Abnormal Glucose Regulation in Patients With Acute Stroke Across China (ACROSS-China). Abnormal glucose regulation in patients with acute stroke across China: prevalence and baseline patient characteristics. Stroke 2012;43:650-657.
    Pubmed
  38. Els T, Klisch J, Orszagh M, Hetzel A, Schulte-Mönting J, Schumacher M, Lücking CH. Hyperglycemia in patients with focal cerebral ischemia after intravenous thrombolysis: influence on clinical outcome and infarct size. Cerebrovasc Dis 2002;13:89-94.
    Pubmed