TY - JOUR
T1 - Opioid inhibition of Ih via adenylyl cyclase
AU - Ingram, Susan L.
AU - Williams, John T.
N1 - Funding Information:
This work was supported by NIH grants from NIDA DAO0141, DA08163, and DA07262. We would like to thank R. A. Travagli, N. V. Marrion, and E. W. McCleskey for helpful comments on this manuscript.
PY - 1994/7
Y1 - 1994/7
N2 - Opioids are coupled through G proteins to both ion channels and adenylyl cyclase. This study describes opioid modulation of the voltage-dependent cation channel, Ih, in cultured guinea pig nodose ganglion neurons. Forskolin, PGE2, and cAMP analogs shifted the voltage dependence of activation of Ih to more depolarized potentials and increased the inward current at -60 mV. Opioids had no effect on In alone, but reversed the effect of forskolin on Ih. This action of opioids was blocked by naloxone. Opioids had no effect on In in the presence of CAMP analogs, suggesting that modulation occurs at the level of adenylyl cyclase. The shift in the voltage dependence of Ih by agents that induce inflammation (i.e., PGE2), is one potential mechanism to mediate an increased excitability. Opioid inhibition of adenylyl cyclase and subsequent inhibition of In may be a mechanism by which opioids inhibit primary afferent excitability and relieve pain.
AB - Opioids are coupled through G proteins to both ion channels and adenylyl cyclase. This study describes opioid modulation of the voltage-dependent cation channel, Ih, in cultured guinea pig nodose ganglion neurons. Forskolin, PGE2, and cAMP analogs shifted the voltage dependence of activation of Ih to more depolarized potentials and increased the inward current at -60 mV. Opioids had no effect on In alone, but reversed the effect of forskolin on Ih. This action of opioids was blocked by naloxone. Opioids had no effect on In in the presence of CAMP analogs, suggesting that modulation occurs at the level of adenylyl cyclase. The shift in the voltage dependence of Ih by agents that induce inflammation (i.e., PGE2), is one potential mechanism to mediate an increased excitability. Opioid inhibition of adenylyl cyclase and subsequent inhibition of In may be a mechanism by which opioids inhibit primary afferent excitability and relieve pain.
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U2 - 10.1016/0896-6273(94)90468-5
DO - 10.1016/0896-6273(94)90468-5
M3 - Article
C2 - 7519024
AN - SCOPUS:0028169932
SN - 0896-6273
VL - 13
SP - 179
EP - 186
JO - Neuron
JF - Neuron
IS - 1
ER -