{'fraction_non_alphanumeric': 0.02394106813996317, 'fraction_numerical': 0.011049723756906077, 'mean_word_length': 5.247126436781609, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Isolated, blood-perfused canine arteries: different vasoconstrictor responses of internal and external carotid arteries to 5-hydroxytryptamine.

Canine carotid arteries were isolated, suspended in a bath and perfused under a constant flow rate with arterial blood led from a support dog. Resting perfusion pressure was set at a constant level over 50 mm Hg. Drugs were administered into the endothelial side of the artery through a cannulated tubing and the response was obtained as pressure changes. This preparation was proved to be superior to usual isolated arterial strips, since its reactivity was kept in a stable condition over 5-10 hours at 37 degrees C. Using this preparation, effects of 5-hydroxytryptamine (5-HT) on the internal and external carotid arteries were investigated in comparison with effects of norepinephrine. In the internal carotid artery, 5-HT caused a much more potent vasoconstriction than norepinephrine. On the other hand, in the external carotid artery, 5-HT caused only slight vasoconstriction, while norepinephrine produced a marked vasoconstriction.