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Impaired Chronotropic Response to Exercise in Mice Lacking Catecholamines in Adrenergic Cells
Author(s) -
Bao Xuping,
Liu Fujun,
Gu Yusu,
Lu Chuanyi M.,
Ziegler Michael G.
Publication year - 2008
Publication title -
annals of the new york academy of sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.712
H-Index - 248
eISSN - 1749-6632
pISSN - 0077-8923
DOI - 10.1196/annals.1410.056
Subject(s) - chronotropic , medicine , endocrinology , phenylethanolamine , adrenergic , phenylethanolamine n methyltransferase , epinephrine , heart rate , catecholamine , tyrosine hydroxylase , blood pressure , dopamine , receptor
To define the in vivo role of adrenergic catecholamines (CAs), we generated a mouse model whereby tyrosine hydroxylase (TH) was knocked out (KO) in phenylethanolamine N ‐methyltransferase–expressing cells. These adrenergic specific TH‐KO mice were viable and grossly normal. Their resting heart rate and blood pressure, as monitored by telemetry, were unchanged. However, when challenged with treadmill exercise, their chronotropic responses were significantly reduced by 14% compared to wild‐type mice. Thus, our data suggest that adrenergic CA is required for normal chronotropic responses to stress, but not required for prenatal and postnatal development or normal cardiovascular function at rest.