“…[9,11,14,19,24,33,37,40,[47][48][49] This controversial [5,19] hypothesis is supported by a delayed onset of long-lasting spasm of the intracranial vessels produced by intracisternal administration of ET-1, [3,47] by an increase in ET-1 levels in CSF after SAH in humans, [11,14,48,49] and by a decrease in the incidence of vasospasm after use of ET-1 receptor antagonists. [8,23,34,38,57] Astrocytes, neurons, and pituitary cells produce ET-1. [10,17,26,29,56] However, ET-1 is also released by endothelial and smooth-muscle cells when they are stimulated by oxyhemoglobin [9,24,40] and by astrocytes when they are stimulated by thrombin.…”