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Sympathetic control of cerebral arteries: specialization in receptor type, reserve, affinity, and distribution
Author(s) -
Bevan John A.,
Duckworth John,
Laher Ismail,
Oriowo M. A.,
McPherson Grant A.,
Bevan Rosemary D.
Publication year - 1987
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.1.3.2887477
Subject(s) - neuroeffector , contraction (grammar) , adrenergic receptor , medicine , sympathetic nervous system , cerebral arteries , receptor , endocrinology , cerebral circulation , norepinephrine , biology , blood pressure , dopamine
The sympathetic neuroeffector system in the mammalian cerebral circulation has a number of distinctive features that reflect its specialized role in this vascular bed: 1 ) there is limited α‐adrenoceptor‐mediated contraction in large vessles that becomes progressively less important with branching; 2 ) contraction is limited by receptor number; small branches often seem to have no functional α adrenoceptors; 3 ) adrenoceptor affinity for norepinephrine is low and so is sensitivity; and 4 ) the dominant α‐adrenoceptor subtype differs in different species and may have unique characteristics in some. There is a mechanism of non‐α‐adrenoceptor‐mediated contraction involving low‐affinity receptor sites—extraceptors—activated by sympathetic nerves. The pig has a seemingly atypical sympathetic mechanism. On the basis of current information the sympathetic neuroeffector mechanisms of the rabbit seem most clearly related to the human. The size, pattern, and distribution of sympathetic control suggest that the role of the sympathetic nerves is to protect the smaller pial arteries against the consequences of sudden increases in sympathetic adrenal discharge. It is not an important mechanism of controlling cerebral blood flow.— B evan , J. A.; D uckworth , J.; L aher , I.; O riowo , M. A.; M c P herson , G. A.; B evan , R. D. Sympathetic control of cerebral arteries: specialization in receptor type, reserve, affinity, and distribution. FASEB J. 1: 193‐198; 1987.