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ADRENOCEPTORS IN INTRACEREBRAL RESISTANCE VESSELS
Author(s) -
MITCHELL G.,
SCRIVEN D.R.L.,
ROSENDORFF C.
Publication year - 1975
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1975.tb07403.x
Subject(s) - tyramine , phenoxybenzamine , isoprenaline , propranolol , reserpine , endocrinology , medicine , vasoconstriction , chemistry , norepinephrine , vasodilation , phentolamine , adrenergic receptor , receptor , dopamine , stimulation
1 The effects of tyramine and isoprenaline on hypothalamic blood flow (HBF) were measured in conscious rabbits. 2 Injections of small doses of tyramine caused an increase in HBF while larger doses caused a decrease in HBF. 3 Isoprenaline injections also produced an increase in HBF. 4 The vasodilatation induced by isoprenaline and the small dose of tyramine was blocked by propranolol. 5 The vasoconstriction induced by the larger doses of tyramine was abolished by phenoxybenzamine. 6 Chemical sympathectomy of the hypothalamus with 6‐hydroxydopamine and depletion of biogenic amines by reserpine also abolished tyramine‐induced vasoconstriction. 7 These results suggest the presence of α‐ and β‐adrenoceptors in cerebral resistance vessels, and that these receptors may be activated by released (endogenous) noradrenaline.