Involvement of endothelial-derived relaxing factors in the regulation of cerebral blood flow.

Despite numerous researches and advances in the present times, delayed cerebral vasospasm remains a severe complication leading to a high mortality and morbidity in patients with subarachnoid hemorrhage (SAH). Since the discovery of endothelium-derived relaxing factor (EDRF) in 1980, its role in delayed cerebral vasospasm after SAH has been widely investigated as well as in regulation of basic cerebral blood flow, pathophysiology of vasoconstriction and application on prevention and treatment of cerebral vasospasm. Among all the EDRFs, nitric oxide has caught the most attention, and the other substances which display similar properties with characteristics of EDRF such as carbon monoxide (CO), hydrogen sulfide (H(2)S), hydrogen peroxide (H(2)O(2)), potassium ion (K(+)) and methane (CH(4)) have also evoked great interest in the research field. This review provides an overview of recent advances in investigations on the involvement of EDRFs in the regulation of cerebral blood flow, especially in cerebral vasospasm after SAH. Possible therapeutic measures and potential clinical implications for cerebral vasospasm are also summarized.