Functional properties of high- and low-affinity receptor subtypes for endothelin-3.
Endothelial cells from brain microvessels express two types of endothelin (ET) receptor. The first receptor subtype (defined as E alpha) shows a high affinity for ET-1, a low affinity for ET-3, and it is coupled to phospholipase C. The second subtype (E beta) shows a high affinity for both ET-1 and ET-3. It is not coupled to phospholipase C, but its activation leads to an increased activity of the Na+/H+ exchanger via a protein kinase C-independent mechanism. Brain astrocytes also express a high-affinity ET-3 receptor. However, unlike that of brain capillary endothelial cells, this receptor is coupled to phospholipase C and it may be a third type of endothelin receptor (E gamma). Thus, it seems that by using both binding and functional criteria, at least three subtypes of endothelin receptor can be distinguished: a low-affinity ET-3 receptor and two high-affinity ET-3 receptors that are coupled to different intracellular signaling pathways.
Frelin
C
C
Institut de Pharmacologie Moléculaire et Cellulaire, CNRS UPR 411, Valbonne, France.
Ladoux
A
A
Marsault
R
R
Vigne
P
P
D000818:Animals; D001253:Astrocytes / Q000201:enzymology / Q000378:metabolism; D002196:Capillaries / Q000378:metabolism / Q000502:physiology; D002478:Cells, Cultured; D016232:Endothelins / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000201:enzymology / Q000378:metabolism; D011493:Protein Kinase C / Q000378:metabolism; D051381:Rats; D011956:Receptors, Cell Surface / Q000378:metabolism*; D017466:Receptors, Endothelin; D010738:Type C Phospholipases / Q000378:metabolism
D016232:Endothelins; D011956:Receptors, Cell Surface; D017466:Receptors, Endothelin; D011493:Protein Kinase C; D010738:Type C Phospholipases