Effects of orexins on myoelectric activity of sphincter of Oddi in fasted rabbits.
OBJECTIVE
To investigate the effects of peripheral orexins on myoelectric activity of the sphincter of Oddi (SO) in fasted rabbits, and carry out a preliminary investigation into the mechanisms underlying these effects.


METHODS
Myoelectric activity of SO in fasted rabbits was recorded before and after intravenous or local application of orexins. The effects of intravenous atropine on orexin-increased myoelectric activity of SO were tested.


RESULTS
Myoelectric activity of SO was activated by both intravenous and local injection of orexin-A or orexin-B. Intravenous application of atropine completely inhibited the excitatory effect of orexins on SO.


CONCLUSIONS
Peripheral application of orexins can increase myoelectric activity of SO in fasted rabbits, which is partially associated with the activation of the cholinergic pathway.
Li
Song-tao
ST
Experimental Center of Basic Medicine and Department of Neurobiology, Third Military Medical University, Chongqing 400038, China.
Chen
Xiao-wei
XW
Zhao
Hong-mei
HM
Li
Na
N
Yan
Jie
J
Hu
Zhi-an
ZA
D000818:Animals; D001285:Atropine / Q000494:pharmacology; D004576:Electromyography / Q000187:drug effects; D005215:Fasting; D005260:Female; D047908:Intracellular Signaling Peptides and Proteins / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D008297:Male; D018727:Muscarinic Antagonists / Q000494:pharmacology; D009479:Neuropeptides / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D018377:Neurotransmitter Agents / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D000068797:Orexins; D011817:Rabbits; D009803:Sphincter of Oddi / Q000502:physiology*; D013268:Stimulation, Chemical
D047908:Intracellular Signaling Peptides and Proteins; D018727:Muscarinic Antagonists; D009479:Neuropeptides; D018377:Neurotransmitter Agents; D000068797:Orexins; D001285:Atropine