nitric oxide protects against stroke

Doug Skrecky (
Mon, 21 Dec 1998 14:32:22 -0800 (PST)

Endres M. Laufs U. Huang Z. Nakamura T. Huang P. Moskowitz MA. Liao JK. Institution
Stroke and Neurovascular Regulation Laboratory, Massachusetts General Hospital, Harvard Medical School, 149 13th Street, Room 6403, Charlestown, MA 02129, USA.
Stroke protection by
3-hydroxy-3-methylglutaryl (HMG)-CoA reductase inhibitors mediated by endothelial nitric oxide synthase.
Proceedings of the National Academy of Sciences of the United States of America. 95(15):8880-5, 1998 Jul 21.
The treatment of ischemic strokes is limited to prophylactic agents that block the coagulation cascade. Here, we show that cholesterol-lowering agents, 3-hydroxy-3-methylglutaryl (HMG)-CoA reductase inhibitors, protect against cerebral injury by a previously unidentified mechanism involving the selective up-regulation of endothelial NO synthase (eNOS). Prophylactic treatment with HMG-CoA reductase inhibitors augments cerebral blood flow, reduces cerebral infarct size, and improves neurological function in normocholesterolemic mice. The up-regulation of eNOS by HMG-CoA reductase inhibitors is not associated with changes in serum cholesterol levels, but is reversed by cotreatment with L-mevalonate and by the downstream isoprenoid, geranylgeranyl pyrophosphate and not by farnesyl pyrophosphate. The blood flow and neuroprotective effects of HMG-CoA reductase inhibitors are completely absent in eNOS-deficient mice, indicating that enhanced eNOS activity by HMG-CoA reductase inhibitors is the predominant if not the only mechanism by which these agents protect against cerebral injury. Our results suggest that HMG-CoA reductase inhibitors provide a prophylactic treatment strategy for increasing blood flow and reducing brain injury during cerebral ischemia.