The CNS lesion scar: new vistas on an old regeneration barrier

The endothelins (ETs) are regulatory peptides, distributed in many organ systems and with potent physiological effects. ETs represent the most powerful vasoconstrictive substances known today. They also act as growth factors and seem to be involved in fetal development. Much data support a pathophysiological role for ETs, especially in diseases of the vascular system, such as hypertension, preeclampsia, ischemic heart disease, subarachnoidal haemorrhage, and cerebral ischemia. The development of drugs affecting ET-receptors and the biosynthesis of ETs presently attract great interest for the establishment of new treatments of diseases in which ETs are involved. Hopefully, the elaboration of more specific ET-receptor ligands will fulfill some of these expectations.