Effects of various intracranial fluids on smooth muscle.

Samples of cerebrospinal fluid (CSF) drawn from patients with subarachnoid hemorrhage, subdural hemorrhage, or brain tumor, as well as control samples from patients without a known cerebral pathological condition, were tested for their ability to contract smooth muscle. Canine middle cerebral artery, canine basilar artery, and rat stomach fundus were used, and contractions were expressed as the percentage of the contraction elicited by a standard dose of 5-hydroxytryptamine. All samples that contained blood produced contractions of the smooth muscle preparations, and despite a large sample no significant differences were observed in the magnitude of the contractions either between preparations or between samples from different groups of patients. Control samples were generally without significant effect. Neither methysergide, a 5-hydroxytryptamine antagonist, nor indomethacin, an inhibitor of prostaglandin synthesis, significantly diminished the contractions induced by bloody CSF, although the calcium antagonist D600 successfully antagonized the response in all groups. D600 was a better antagonist of the action of blood-containing CSF on cerebral artery than on stomach fundus. Samples obtained from patients with angiographic evidence of vasospasm were significantly more active than those obtained from patients without vasospasm, but the latter retained considerable activity.