Contrasting effects of presynaptic 2-adrenergic autoinhibition and pharmacologic augmentation of presynaptic inhibition on sympathetic heart rate control
نویسندگان
چکیده
Tadayoshi Miyamoto, Toru Kawada, Yusuke Yanagiya, Tsuyoshi Akiyama, Atsunori Kamiya, Masaki Mizuno, Hiroshi Takaki, Kenji Sunagawa, and Masaru Sugimachi Department of Physical Therapy, Faculty of Health Sciences, Morinomiya University of Medical Sciences; and Department of Cardiovascular Dynamics, Advanced Medical Engineering Center, and Department of Cardiac Physiology, National Cardiovascular Center Research Institute, Osaka; and Department of Cardiovascular Medicine, Graduate School of Medical Sciences, Kyusyu University, Fukuoka, Japan
منابع مشابه
Contrasting effects of presynaptic alpha2-adrenergic autoinhibition and pharmacologic augmentation of presynaptic inhibition on sympathetic heart rate control.
Presynaptic alpha2-adrenergic receptors are known to exert feedback inhibition on norepinephrine release from the sympathetic nerve terminals. To elucidate the dynamic characteristics of the inhibition, we stimulated the right cardiac sympathetic nerve according to a binary white noise signal while measuring heart rate (HR) in anesthetized rabbits (n = 6). We estimated the transfer function fro...
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The regulation of dopamine and serotonin synthesis in rat brain striatal synaptosomes has been studied using HPLC methods. Noradrenaline was shown to markedly inhibit both the synthesis of dopamine and serotonin. The response of the synaptosomes to the concentrations of noradrenaline appeared to be biphasic, a very effective inhibition occurring at low concentrations (1-5 µm) and a relativ...
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Using a perfused innervated rat heart model, we studied the sex difference in the sympathetic nerve stimulation-induced norepinephrine release and its presynaptic alpha 2-adrenergic inhibition in normoxic and ischemic conditions. During normoxic perfusion, the alpha 2-adrenoceptor antagonist rauwolscine resulted in a higher overflow of norepinephrine during nerve stimulation in females than in ...
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Presynaptic receptors for dopamine, histamine and serotonin that are located on dopaminergic, histaminergic and sertonergic axon terminals, respectively, function as autoreceptors. Presynaptic receptors also occur as heteroreceptors on other axon terminals. Auto- and heteroreceptors mainly affect Ca(2+) -dependent exocytosis from the receptor-bearing nerve ending. Some additionally subserve oth...
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