MODELS FOR INVESTIGATING THE AETIOLOGY OF CEREBRAL ARTERIAL SPASM: COMPARATIVE RESPONSES OF THE HUMAN BASILAR ARTERY WITH RAT COLON, ANOCOCCYGEUS, STOMACH FUNDUS, AND AORTA AND GUINEA‐PIG ILEUM AND COLON

1 The pharmacological similarity between human basilar artery and a number of isolated tissues (rat colon, anococcygeus, stomach fundus and aorta and guinea‐pig ileum and colon) has been assessed during investigations of the aetiology of cerebral arterial spasm. 2 The responses of each of the six tissues to human normal and abnormal cerebrospinal fluid (CSF) and to human serum were compared with those of the human isolated basilar artery. 3 These studies revealed the presence of a vasodilator factor in CSF from subarachnoid haemorrhage patients and several tissues may be of use for further work in identifying the vasoactive substances in CSF. 4 No tissue displayed exactly the same spectrum of biological reactivity as the human basilar artery. The rat stomach fundus showed the closest similarity and was further studied for similarities in drug‐induced responses. 5 The rat stomach fundus, like the human basilar artery, was contracted by 5‐hydroxytryptamine, prostaglandin F2a and histamine and relaxed by dopamine. However, noradrenaline relaxed the fundus but contracted the basilar artery.