Changes of endothelin during cerebral vasospasm after experimental subarachnoid hemorrhage.

Laser-Doppler flowmetry was employed in the observation of regional cortical blood flow (rCBF) after experimental subarachnoid hemorrhage (SAH) in anesthetized rats and the contents of endothelin (ET) in the cerebral-spinal fluid (CSF), plasma, hypothalamus, cerebral cortex, cerebellum and medulla were simultaneously measured. There was a biphasic change of rCBF after SAH. The contents of ET in CSF, plasma and hypothalamus rose prominently in the early stage after SAH, and the ET-increase in CSF and hypothalamus was earlier than that in plasma. The changes of ET contents in CSF correlated well with that in hypothalamus. Our results suggest that ET probably is an early important factor which induces cerebral vasospasm (CVS) after SAH. The increase of ET in CSF, which may originate from the hypothalamus, might play a more important role in the development of CVS after SAH than that in plasma.