Pan W, Vallance K, Kastin A J
Department of Neurology, Tulane University, New Orleans, Louisiana 70112-1262, USA.
Exp Neurol. 1999 Dec;160(2):454-9. doi: 10.1006/exnr.1999.7215.
Transforming growth factor alpha (TGFalpha) is a cytokine that belongs to the epidermal growth factor (EGF) family of growth factors. EGF has a fast and saturable entry from blood to brain that is inhibitable by TGFalpha (18). In this report, we studied the passage of TGFalpha from blood to brain after an i.v. bolus injection. Using radioactively labeled peptide, we found that TGFalpha had an apparent rate of entry of 0.7 microl/g/min. However, most of the TGFalpha was trapped in the capillary endothelial cells of the cerebral vasculature rather than entering the brain parenchyma. No saturation was detected. TGFalpha was relatively stable in blood for 20 min after i.v. injection, but dissociation of the isotope 125I was more evident in brain. The accumulation of TGFalpha in the cerebral vasculature was similar to that of amyloid-beta protein1-40. Therefore, we conclude that TGFalpha from the periphery interacts with the blood-brain barrier without substantial uptake into brain parenchyma. This raises the possibility that TGFalpha might be involved in intracranial vascular disorders such as angiopathy.
转化生长因子α（TGFα）是一种细胞因子，属于表皮生长因子（EGF）家族的生长因子。EGF从血液进入大脑的过程迅速且具有饱和性，这一过程可被TGFα抑制（18）。在本报告中，我们研究了静脉推注后TGFα从血液进入大脑的情况。使用放射性标记的肽，我们发现TGFα的表观进入速率为0.7微升/克/分钟。然而，大部分TGFα被困在脑血管的毛细血管内皮细胞中，而不是进入脑实质。未检测到饱和现象。静脉注射后，TGFα在血液中相对稳定20分钟，但同位素125I在大脑中的解离更为明显。TGFα在脑血管中的积累与淀粉样β蛋白1-40相似。因此，我们得出结论，外周的TGFα与血脑屏障相互作用，但不会大量摄取到脑实质中。这增加了TGFα可能参与颅内血管疾病如血管病变的可能性。
