Cerebral vascular smooth muscle potassium channels and their possible role in the management of vasospasm.
One of the promising therapeutic uses of the potassium channel openers is in the management of cerebral vasospasm, a prolonged vasoconstriction of major cerebral arteries which follows aneurysmal subarachnoid haemorrhage. In this review, we first summarize the properties of potassium channels in cerebral vascular smooth muscle. Calcium-activated and ATP-dependent potassium channels are the major potassium channels identified in the cerebrovascular smooth muscle and both are believed to play a role in the regulation of cerebrovascular smooth muscle tone. The calcium-activated potassium channels can be activated by depolarization, by elevation of internal calcium and by some vasodilators. Some neuropeptides and potassium channel openers open the ATP-dependent potassium channels and produce vasodilation. We then review the effects of both synthetic and endogenous potassium channel openers in the cerebrovascular system, discuss their efficacy in the management of models of cerebrovascular spasm, and outline the clinical promise of these agents.
Zhang
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Department of Surgery, University of Chicago, IL 60637.
Cook
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D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D001578:Benzopyrans / Q000494:pharmacology / Q000627:therapeutic use; D002118:Calcium / Q000494:pharmacology; D019806:Cromakalim; D004594:Electrophysiology; D006146:Guanidines / Q000494:pharmacology / Q000627:therapeutic use; D002546:Ischemic Attack, Transient / Q000188:drug therapy*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000378:metabolism; D009479:Neuropeptides / Q000494:pharmacology / Q000627:therapeutic use; D009536:Niacinamide / Q000031:analogs & derivatives / Q000494:pharmacology / Q000627:therapeutic use; D020108:Nicorandil; D009569:Nitric Oxide / Q000494:pharmacology / Q000627:therapeutic use; D020110:Pinacidil; D015221:Potassium Channels / Q000187:drug effects / Q000502:physiology*; D011758:Pyrroles / Q000494:pharmacology / Q000627:therapeutic use; D014661:Vasoconstriction / Q000187:drug effects; D014665:Vasodilator Agents / Q000494:pharmacology* / Q000627:therapeutic use
D001578:Benzopyrans; D006146:Guanidines; D009479:Neuropeptides; D015221:Potassium Channels; D011758:Pyrroles; D014665:Vasodilator Agents; D019806:Cromakalim; D009536:Niacinamide; D020108:Nicorandil; D009569:Nitric Oxide; D020110:Pinacidil; D000255:Adenosine Triphosphate; D002118:Calcium