中国神经再生研究(英文版) ›› 2016, Vol. 11 ›› Issue (3): 392-393.doi: 10.4103/1673-5374.179038

• 观点:脑损伤修复保护与再生 • 上一篇    下一篇

考尼伐坦治疗脑卒中的预临床研究进程

  

  • 收稿日期:2016-01-15 出版日期:2016-03-15 发布日期:2016-03-15
  • 基金资助:

    该研究由美国瑞典医疗中心资金支持。

Recent advances and future directions in preclinical research of arginine-vasopressin (AVP) receptor blocker conivaptan in the context of stroke

Emil Zeynalov, Susan M. Jones   

  1. Swedish Medical Center, Neurotrauma Research Department Englewood, Englewood, CO, USA
  • Received:2016-01-15 Online:2016-03-15 Published:2016-03-15
  • Contact: Emil Zeynalov, M.D.,emil.zeynalov@healthonecares.com.
  • Supported by:

    Funding provided by the Swedish Medical Center to J. Paul Elliott, MD. Author Contributions: EZ-writing of the manuscript; SMJ-writing of the manuscript.

摘要:

脑卒中发病过程中会伴随威胁生命的病理生理性响应,包括脑水肿、颅内压升高、血脑障壁破裂、脑梗塞和永久性组织损伤。脑水肿的发展归咎于大脑细胞内和细胞外的膈间水积累,这会引起脑容量增加以及颅内压升高。而脑组织压缩对大脑血流量的冲击造成了二次脑损伤。通常情况下,脑卒中的临床表现还伴随着由低钠血症引起的抗利尿激素分泌异常综合征或者脑性盐耗综合征。抗利尿激素分泌异常综合征是抗利尿激素不受控制的分泌所引起的,也称精氨酸升压素。精氨酸升压素作用在V1a 和V2受体上,进而引发血管收缩,血小板聚集和水分保持,并伴随着血容量过多或者血量正常的低钠血症和低血浆渗透度的情况。当今治疗脑水肿的方法(例如开颅减压术或者高渗盐溶液)都没有完全地解决由抗利尿激素分泌异常综合征和脑性盐耗综合征引起的并发症。因此,新的研究方法需要确定和认定脑卒中诱发的脑水肿的准确成因。文章表示已有许多研究表明,精氨酸升压素受体介导了多种事件级联,这些程序导致了血管收缩,血小板聚集,水分保持和低钠血症。V1a受体最初发现于血管平滑肌细胞和血小板中,并且,由精氨酸升压素激活的V1a受体又引发了血管收缩和血小板聚集。因此,缺血性脑损伤后的抑制V1a受体可能有助于预防血管收缩和血块形成,这一状况可能也会增加局部脑血流量,并减轻脑水肿程度。V2受体位于肾收集管,由精氨酸升压素激活的V2受体会导致水分再吸收增加以及血浆钠和渗透度降低。V2受体的药物抑制也显示出能够增加肾脏中的水分泌,增加血液中钠浓度的作用,因此,也可能会帮助有效控制脑水肿。

Abstract:

Stroke is a major cause of mortality and permanent disability. The onset of stroke is followed by life-threatening pathophysiological responses including brain edema, elevation of intracranial pressure, disruption of blood-brain barrier (BBB), brain infarct and permanent tissue damage. Brain edema develops due to accumulation of water in intracellular and extracellular compartments of the brain, which causes an increase in brain volume and elevation of intracranial pressure. Compression of the brain tissue has an impact on cerebral blood flow which results in secondary brain injury. Often, clinical presentation of stroke is accompanied by hyponatremia caused either by the syndrome of inappropriate release of antidiuretic hormone (SIADH) or cerebral salt wasting (CSW). SIADH is the result of uncontrolled secretion of antidiuretic hormone (ADH) also called arginine-vasopressin (AVP). AVP acts on V1a and V2 receptors triggering vasoconstriction, platelet aggregation, and water retention followed by hypervolemic or normovolemic hyponatremia and low plasma osmolality. Current therapeutic applications against brain edema (such as decompression craniotomy or hypertonic saline) do not fully address complications caused by SIADH or CSW.  Therefore, new research approaches are required to identify and target precise causes of stroke-induced brain edema. Many studies report that AVP receptors (V1a and V2) mediate cascades of events that result in vasoconstriction, platelet aggregation, water retention, and hyponatremia. V1a receptors are found primarily in vascular smooth muscle cells and platelets, and activation of V1a receptors by AVP induces vasoconstriction and platelet aggregation. Therefore, blocking of V1a receptors after ischemic brain injury may potentially prevent vasoconstriction and clot formation, which may also improve regional cerebral blood flow (rCBF), and lower the magnitude of brain edema. V2 receptors are localized in the collecting ducts of the kidneys, and activation of V2 receptors by AVP leads to increased water reabsorption and reduction of plasma sodium and osmolality. Pharmacological inhibition of V2 receptors has been shown to increase water secretion (aquaresis) in the kidneys, raising sodium concentration in the blood and thus may help control brain edema.