ET-1 induces cortical spreading depression via activation of the ETA receptor/phospholipase C pathway in vivo.
Recently, it has been shown that brain topical superfusion of endothelin (ET)-1 at concentrations around 100 nM induces repetitive cortical spreading depressions (CSDs) in vivo. It has remained unclear whether this effect of ET-1 is related to a primary neuronal/astroglial effect, such as an increase in neuronal excitability or induction of interastroglial calcium waves, or a penumbra-like condition after vasoconstriction. In vitro, ET-1 regulates interastroglial communication via combined activation of ET(A) and ET(B) receptors, whereas it induces vasoconstriction via single activation of ET(A) receptors. We have determined the ET receptor profile and intracellular signaling pathway of ET-1-induced CSDs in vivo. In contrast to the ET(B) receptor antagonist BQ-788 and concentration dependently, the ET(A) receptor antagonist BQ-123 completely blocked the occurrence of ET-1-induced CSDs. The ET(B) receptor antagonist did not increase the efficacy of the ET(A) receptor antagonist. Direct stimulation of ET(B) receptors with the selective ET(B) agonist BQ-3020 did not trigger CSDs. The phospholipase C (PLC) antagonist U-73122 inhibited CSD occurrence in contrast to the protein kinase C inhibitor Gö-6983. Our findings indicate that ET-1 induces CSDs through ET(A) receptor and PLC activation. We conclude that the induction of interastroglial calcium waves is unlikely the primary cause of ET-1-induced CSDs. On the basis of the receptor profile, likely primary targets of ET-1 mediating CSD are either neurons or vascular smooth muscle cells.
Kleeberg
Jörg
J
Department of Neurology, Humboldt-Universität, 10117 Berlin, Germany.
Petzold
Gabor C
GC
Major
Sebastian
S
Dirnagl
Ulrich
U
Dreier
Jens P
JP
D000818:Animals; D016718:Arachidonic Acid / Q000494:pharmacology; D001253:Astrocytes / Q000187:drug effects; D002450:Cell Communication / Q000187:drug effects; D013181:Cortical Spreading Depression / Q000187:drug effects*; D065130:Endothelin A Receptor Antagonists; D019332:Endothelin-1 / Q000494:pharmacology*; D016232:Endothelins / Q000494:pharmacology; D004963:Estrenes / Q000494:pharmacology; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D009842:Oligopeptides / Q000494:pharmacology; D010296:Parietal Lobe / Q000187:drug effects; D010446:Peptide Fragments / Q000494:pharmacology; D010456:Peptides, Cyclic / Q000494:pharmacology; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D010880:Piperidines / Q000494:pharmacology; D011760:Pyrrolidinones / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D044022:Receptor, Endothelin A / Q000187:drug effects*; D015398:Signal Transduction / Q000187:drug effects*; D010738:Type C Phospholipases / Q000502:physiology*
D065130:Endothelin A Receptor Antagonists; D019332:Endothelin-1; D016232:Endothelins; D004963:Estrenes; D009842:Oligopeptides; D010446:Peptide Fragments; D010456:Peptides, Cyclic; D010726:Phosphodiesterase Inhibitors; D010880:Piperidines; D011760:Pyrrolidinones; D044022:Receptor, Endothelin A; C060229:1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione; C075771:BQ 3020; D016718:Arachidonic Acid; C086539:BQ 788; D010738:Type C Phospholipases; C072247:cyclo(Trp-Asp-Pro-Val-Leu)