Abstract
Bradykinin receptors are believed to contribute to hyperalgesia under conditions of neuropathic pain. Using calcium imaging we investigated responses to B1 and B2 agonists on isolated rat dorsal root ganglion neurons. No response to the B1 agonist was detected, whereas 12% of neurons responded to the B2 agonist. Northern blot analysis confirmed the lack of B1 receptor expression in dorsal root ganglia, as B1 mRNA was neither detected under normal conditions nor after nerve injury. In the calcium imaging experiments, agonists were applied with an elevated superfusion flow rate to avoid tachyphylaxis to the drug. Normal external solution applied at this flow rate constituted a mechanical stimulus causing a response in some neurons. Thus, in comparable set-ups mechanosensitivity has first to be tested to avoid masking effects.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Blotting, Northern
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Bradykinin / agonists*
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Bradykinin / metabolism
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Calcium / metabolism
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Calcium Signaling / drug effects
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Calcium Signaling / physiology
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Cells, Cultured / cytology
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Cells, Cultured / drug effects
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Cells, Cultured / metabolism
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Drug Administration Schedule
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Fluorescent Dyes
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Fura-2
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Ganglia, Spinal / cytology
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Ganglia, Spinal / drug effects
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Ganglia, Spinal / metabolism*
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Intracellular Fluid / drug effects
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Intracellular Fluid / metabolism
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Kallidin / analogs & derivatives*
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Kallidin / pharmacology
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Male
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Neuralgia / metabolism*
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Neuralgia / physiopathology
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Neurons, Afferent / cytology
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Neurons, Afferent / drug effects
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Neurons, Afferent / metabolism*
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Peripheral Nervous System Diseases / metabolism*
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Peripheral Nervous System Diseases / physiopathology
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RNA, Messenger / drug effects
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RNA, Messenger / metabolism
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Rats
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Rats, Sprague-Dawley
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Rats, Wistar
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Receptor, Bradykinin B1
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Receptors, Bradykinin / agonists*
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Receptors, Bradykinin / genetics*
Substances
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Fluorescent Dyes
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RNA, Messenger
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Receptor, Bradykinin B1
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Receptors, Bradykinin
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Kallidin
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kallidin, des-Arg(10)-
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Bradykinin
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Calcium
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Fura-2