Prevention of hypoxic brain oedema by the administration of vasopressin receptor antagonist OPC-31260
Institute of Physical Education and Sport Sciences, Faculty of Juhász Gyula Teacher Training College, University of Szeged, H-6725, Szeged, Topolya sor 2-4, Hungary. Progress in brain research
(Impact Factor: 2.83).
01/2008; 170:519-25. DOI: 10.1016/S0079-6123(08)00439-1
The numerous situations which can result in cerebral hypoxic damage occur in newborn infants and in the elderly. In research aimed at more effective therapeutic intervention in ischaemic disorders of the brain, the animal model used and the principles of the causal therapy should be better outlined. The effects of the non-peptide AVPR (V2) antagonist 5-dimethylamino-1-[4-(2-methylbenzoylamino) benzoyl]-2,3,4,5-tetrahydro-1H-benzazepine hydrochloride (OPC-31260) on the cerebral oedema induced by general cerebral hypoxia were studied in rats. The general cerebral hypoxia was produced by bilateral common carotid ligation in Sprague-Dawley rats of the CFY strain. By 6h after the ligation, half of the rats had died, but the survival rate was significantly higher following OPC-31260 administration. Electron microscopic examinations revealed typical ischaemic changes after the carotid ligation, and OPC-31260 treatment did not significantly reduce the hypoxic signs in the brain cortex; only a certain decrease in the pericapillary oedema was observed. The carotid ligation increased the brain contents of water and Na(+) and enhanced the plasma AVP level. The increased brain water and Na(+) accumulation was prevented by OPC-31260 administration, but the plasma AVP level was further enhanced by OPC-31260. These results demonstrate the important role of AVP in the development of the disturbances in brain water and electrolyte balance in response to general cerebral hypoxia. The carotid ligation-induced cerebral oedema was significantly reduced following oral OPC-31260 administration. The protective mechanism exerted by OPC-31260 stems from its influence on the renal AVPR (V2). These observations might suggest an effective approach to the treatment of global hypoxia-induced cerebral oedema in humans.
Available from: link.springer.com
Neurocritical Care 06/2009; 11(1):1-4. DOI:10.1007/s12028-009-9224-x · 2.44 Impact Factor
Available from: Shin Nakayama
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ABSTRACT: Aquaporin-4 (AQP4) plays an important role in the evolution of ischemia-evoked cerebral edema. Experimental studies have also demonstrated anti-edema effects of arginine-vasopressin (AVP) antagonists. In a well-characterized murine model of ischemic stroke, we tested the hypotheses that treatment with selective AVP V(1) but not V(2) receptor antagonist (1) attenuates injury volume and ischemia-evoked cerebral edema; and (2) modulates ischemia-evoked AQP4 expression.
Isoflurane-anesthetized adult male C57bl/6 mice were subjected to 60 min of middle cerebral artery occlusion (MCAO) by the intraluminal suture technique. Adequacy of MCAO and reperfusion was monitored with laser-Doppler flowmetry over the ipsilateral parietal cortex. Mice were treated with intracerebroventricular injection of selective AVP V(1) and V(2) receptor antagonist or control vehicle (0.9% saline). Infarct volume (tetrazolium staining), cerebral edema (wet-to-dry ratios) and AQP4 protein expression (immunoblotting) were determined in different treatment groups in separate sets of experiments at 24 h of reperfusion.
Infarct volume (percentage of contralateral structure; mean +/- SEM) was significantly attenuated in mice treated with 500 ng V(1) receptor antagonist as well as at a dose of 1000 ng compared to controls. However, there was no difference in infarct volume following treatment with 1000 ng V(2) antagonist as compared to controls. Water content in the ischemic hemisphere was significantly attenuated with V(1) receptor antagonist (1000 ng) but not with V(2) receptor antagonist as compared to controls. Treatment with AVP V(1) receptor antagonist (1000 ng) but not V(2) receptor antagonist, significantly upregulated AQP4 protein expression (% beta-actin) compared to saline-treated mice in ipsilateral (ischemic) cerebral cortex.
These data demonstrate that following experimental stroke AVP V(1) receptor antagonism: (1) attenuates injury volume and ischemia-evoked cerebral edema; (2) modulates AQP4 expression; and (3) may serve as an important therapeutic target for neuroprotection and ischemia-evoked cerebral edema.
Neurocritical Care 10/2009; 12(1):124-31. DOI:10.1007/s12028-009-9277-x · 2.44 Impact Factor
Journal of cardiothoracic and vascular anesthesia 11/2009; 24(2):330-47. DOI:10.1053/j.jvca.2009.09.006 · 1.46 Impact Factor
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