title: [Effect of G protein in the dual regulation of opioid receptor agonist on the delayed rectified potassium channels].
abstract: OBJECTIVE
  To observe the role of G protein in the dual regulation of opioid receptor agonist on the delayed rectified potassium channels.
  
  
  METHODS
  Using whole-cell patch-clamp techniques applied to NG108-15 cells, investigate the effect of opioid receptor agonist on the delayed rectified potassium channels by administration of Guanosine-5'-0'-2-thiociphosphate (GDP beta S), Pertusis Toxin (PTX), Tetroacetic acid nueleoside diphosphate kinase (NDPK) and Adenosine-3' 5' cyclic monophosphate cAMP in the pipette solution.
  
  
  RESULTS
  (1) GDP beta S could block the changes induced by both high and low concentration of (D-Pen2.5)-enkephalin (DPDPE) (P < 0.05). (2) PTX could inhibit the excitative regulation on K+ channel by high concentration of DPDPE (P < 0.05). But CTX had no effect on K+ channel caused by DPDPE. (3) UDP could block the excitative effect of K+ channel by high concentration of NDPK, while have no changes on the inhibitory effect caused by low concentration of opioid agonists. (4) cAMP took part in the regulation in high concentration of agonist administration (P < 0.05), while no changes for low concentration of agonists.
  
  
  CONCLUSIONS
  Dual changes were observed on delayed rectifier potassium channel by agonist treatment on NG108-15 cells. The excitative effect was Gi/o coupled in high concentration of agonist incubation, related to cAMP. While the inhibitory effect was possibly induced by G protein beta gamma subunit directly.
authors.affiliation: Department of Pharmacology, Institute of Basic Medical Sciences, CAMS, PUMC, Beijing 100005, China. caiying_ye@sohu.com
authors.forename: Cai-ying
authors.initials: CY
authors.lastname: Ye
authors.forename: Qing-xia
authors.initials: QX
authors.lastname: Li
authors.forename: Xiao-li
authors.initials: XL
authors.lastname: Yu
authors.forename: Jing-jing
authors.initials: JJ
authors.lastname: Qi
authors.forename: Juan
authors.initials: J
authors.lastname: Li
authors.forename: De-chang
authors.initials: DC
authors.lastname: Zhang
mesh_terms: D000818:Animals; D020881:Enkephalin, D-Penicillamine (2,5)- / Q000494:pharmacology; D019204:GTP-Binding Proteins / Q000502:physiology*; D005910:Glioma / Q000378:metabolism / Q000473:pathology; D006157:Guanosine Monophosphate / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D006822:Hybrid Cells / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D009447:Neuroblastoma / Q000378:metabolism / Q000473:pathology; D018408:Patch-Clamp Techniques; D037342:Pertussis Toxin / Q000494:pharmacology; D024661:Potassium Channels, Inwardly Rectifying / Q000378:metabolism*; D051381:Rats; D011957:Receptors, Opioid / Q000819:agonists*; D013873:Thionucleotides / Q000493:pharmacokinetics
chemical_list: D024661:Potassium Channels, Inwardly Rectifying; D011957:Receptors, Opioid; D013873:Thionucleotides; C077838:guanosine-5'-O-(S-(3-bromo-2-oxopropyl))thiophosphate; D006157:Guanosine Monophosphate; D020881:Enkephalin, D-Penicillamine (2,5)-; D037342:Pertussis Toxin; D019204:GTP-Binding Proteins