HUMAN CEREBROMICROVASCULAR ENDOTHELIUM--DISTINCT PEPTIDERGIC RESPONSES IN VITRO

人脑微血管内皮——体外独特的肽反应

• 批准号: 6163037
• 负责人: M SPATZ
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF NEUROLOGICAL DISORDERS AND STROKE
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6163037
• 关键词: amiloride; antiport; blood brain barrier; brain cell; calmodulin; capillary; endothelin; human tissue; ion transport; laboratory rat; membrane transport proteins; neuropeptides; protein kinase C; sodium potassium exchanging ATPase; staurosporine; tissue /cell culture; tumor necrosis factor alpha; vascular endothelium; vasoactive agent

We have previously established that endothelin-1 (ET-1) induces receptor (ET/A) mediated cerebromicrovascular permeability changes and may function on a proinflammatory agent. Lately, we have also demonstrated that ET-1 and ET-3 modulates the ion transport systems (Na+-K+-ATPase and Na+/K+/Cl--cotransport) in endothelial cells derived from capillaries of rat brain. The experiments described here examined the effect of endothelin (ET-1) on another ion transport pathway, namely sodium/hydrogen (Na+/H+ exchange system) in rat brain capillary endothelium (RBEC). ET-1, ET-2 and ET-3 stimulated Na+ uptake into REBC with similar half- maximal stimulation (EC50 ) values (0.7, 0.6, and 1.1 nM, respectively). This reaction was inhibited by the Na+ /H+ antiport inhibitor, N-(ethyl- N-isopropyl)-amiloride (EIPA). The selective endothelin A (ET/A ) receptor-antagonist [Cyclo-D-Trp-D-Asp-Pro-D-Val-Leu BQ123], but not endothelin B (ET/B) receptor-antagonists[(Cys11, Cys15)-ET-1 (IRL1038) or N-cis-2,6-dimethylprperidinocarbonyl-L-gamma MeLeu-D-trp (COOMe)-D- Nle-ONa (BQ788)], inhibited both ET-1 and ET-3 stimulated Na+ receptor mediation. The protein kinase C (PKC) activator [phorbol 12-myristate 13-acetate (MAO) failed to stimulate Na+uptake. The calcium-calmodulin (CaM) inhibitor (W7) reduced ET-1 stimulate Na+uptake by 50%, whereas the PKC inhibitor (staurosporine) had no effect, indicating that ET-1 stimulation of Na+ /H+ antiport system is linked to a CaM-dependent and PKC-independent pathway. The present results further support the idea that endothelins play a role in regulating ion transport across the blood-brain barrier..

我们之前已经确定内皮素-1 （ET-1）诱导受体