人体血管内皮细胞的血小板激活因子的产生:有证据表明需要特定的激动因子和由前环素调节
Circulation
|October 1, 1985
概括
人的静脉内皮细胞产生血小板激活因子 (PAF) 当受到特异性激动剂,如血栓激素刺激时. 内源性前列环素生产可以调节这种PAF合成,影响血小板激活和血管损伤.
科学领域:
- 内皮细胞生物学 内皮细胞生物学
- 脂质媒介合成的合成
- 血管炎症是一种血管炎症.
背景情况:
- 内皮细胞在血管平衡和炎症中起着至关重要的作用.
- 血小板激活因子 (PAF) 是一种强大的脂质媒介,参与血小板和白细胞激活.
- 了解内皮细胞对刺激的反应是理解血管事件的关键.
研究的目的:
- 为了研究由人类静脉内皮细胞产生的血小板激活因子 (PAF).
- 为了确定刺激内皮细胞中PAF合成的特定激素.
- 探索前列腺素在调节内皮PAF产生中的作用.
主要方法:
- 人类静脉内皮细胞的初级培养.
- 使用激动剂的刺激,如人体血栓素和离子体A23187.7.
- 使用染色体技术和生物试验识别PAF.
- 评估前环素对PAF产生的影响,包括使用印米他辛.
主要成果:
- 当被特定的激动剂刺激时,内皮细胞会合成PAF,特别是血栓素和A23187.
- 培养PAF是一种特定的反应,而不是一般细胞干扰的结果.
- 作为内皮细胞产物的前环素减弱了PAF的合成.
- 印米他辛是一种前环素合成抑制剂,增强了PAF的产生.
结论:
- 培养的人体内皮细胞能够在对特定刺激的反应中合成PAF.
- 内皮PAF的产生可以通过内源性产生的前环素来调节.
- 内皮细胞具有通过PAF合成影响血小板和白细胞活动的潜力,影响血管生理和损伤.
相关概念视频
Mechanism of Angiogenesis
Blood vessel formation starts early during embryonic development, around day 7. In the extraembryonic yolk sac, mesodermal precursor cells called hemangioblast proliferate and differentiate into angioblast. Angioblasts express vascular endothelial growth factor receptor 2 or VEGFR2, which binds VEGF-A, a proangiogenic factor, guiding blood vessel formation. VEGF signaling promotes angioblasts to form a blood island in the developing embryo. Angioblasts further differentiate, giving rise to...
Regulation of Angiogenesis and Blood Supply
Rapidly dividing tumors, embryos, and wounded tissues require more oxygen than usual, lowering the oxygen concentration in the blood. At low oxygen or hypoxic conditions, an oxygen-sensitive transcription factor called the hypoxia-inducible factor 1 or HIF1 is activated. HIF1 is a dimeric protein of alpha (ɑ) and beta (β) subunits. Under optimal oxygen conditions, HIF1β is present in the nucleus while HIF1ɑ remains in the cytosol. HIF1ɑ is hydroxylated by prolyl hydroxylase and factor...
Intracellular Signaling Affects Focal Adhesions
Integrins act both as extracellular input receivers and as intracellular processing activators. As their name suggests, integrins are entirely integrated into the membrane structure. Their hydrophobic membrane-spanning regions interact with the phospholipid bilayer's hydrophobic region. These membrane receptors provide extracellular attachment sites for effectors like hormones and growth factors. They activate intracellular response cascades when their effectors are bound and active.
Some...
Some...
Vascular Spasm
The vascular phase, also known as vasospasm, is the initial stage of hemostasis, crucial for preventing excessive bleeding when a blood vessel is injured. After a vessel is cut, nerves in the damaged area trigger pain and other sensory impulses. Simultaneously, the smooth muscles in the vessel wall contract, resulting in a vascular spasm. This contraction reduces the vessel's diameter at the injury site, slowing or stopping blood loss through the vessel wall. Vascular spasms typically last for...
Formation of the Platelet Plug
The platelet phase, the second stage of hemostasis, commences around 15-20 seconds after an injury. It follows and overlaps with the vascular phase, during which blood vessels constrict to minimize blood loss.
As the injured blood vessel contracts, endothelial cells undergo contraction, revealing collagen fibers in the basement membrane and underlying connective tissue. Furthermore, the plasma membrane of endothelial cells becomes adhesive, preparing the site for platelet adhesion. Platelets...
As the injured blood vessel contracts, endothelial cells undergo contraction, revealing collagen fibers in the basement membrane and underlying connective tissue. Furthermore, the plasma membrane of endothelial cells becomes adhesive, preparing the site for platelet adhesion. Platelets...
Clot Retraction and Fibrinolysis
After a fibrin clot is formed, the next step is clot retraction, a vital process facilitated by platelet contractile proteins, such as actin and myosin. These proteins pull the fibrin strands closer together and condense the clot. This action reduces the size of the clot, creating a smaller, denser structure that effectively seals off the damaged vessel. Clot retraction consolidates the clot and helps with wound healing by bringing the edges of the damaged blood vessel closer together.


